Tandy 1000SX Technical Service Data

HOWARD

W. SAMS

&

COMPANY

COMPUTERFACTS

Technical

Service Data

TANDY®

MODEL

1000SX

COMPUTER

FEATURES COMPLETE

SCHEMATICS •

PRELIMINARY

SERVICE CHECKS

•

TROUBLESHOOTING

TIPS

EASY-READ

WAVEFORMS

•

REPLACEMENT

PARTS

LISTS •

SEMICONDUCTOR CROSS REFERENCE

giMflC

COMPUTERFACTS"

TANDY

MODEL

1000SX

PRELIMINARY

provides the user with a

data

This

service

tion and repair

tions.

Check all

nection

tool

which is

interconnecting cables for

and correct hook-up

SERVICE CHECKS

designed for quick

of Computer

time-saving

system malfunc-

good con-

before making

Isola-

service checks.

Always

or disconnecting
erals.

x

ca

o

O

v.

°

Q
<

uj

I-

Q

o

s

Disconnect al

Computer system to

ma I functions.

Replacement or repair of the

System Board, Keyboard, Disk Drives or

nectors

has been isolated.

turn

may

TEST EQUIPMENT

Computer Off before connecting

the

connectors,

external peripherals

I

boards or

eliminate possible external

Power Supply,

necessary after the

be

AND

TOOLS

malfunction

periph-

from the

con-

o

TEST EQUIPMENMT

o

Digital Volt/Ohm Meter

Probe

Logic

Frequency

Counter

Monitor with Audio Input

Disk Drive Tester or Test

Program

TOOLS

Head Cleaning

Contact and Switch

Phillips

Flat Blade Screwdriver

1/4"

Insertion and Removal Tools 20,

IC

pin

Low Wattage

Deso

^ttb ^bb in ^Bt

m MMMlm

The fisting

constitute in any

by Howard W. Sams

such replacement part. The numbers of

compiled from information furnished

by the manufacturers of the particular

listed.

**s$^

Howard

'm

4300 West 62nd Street,

any

of

available replacement part herein

recommendation, warranty

case a

& Co. as to

the quality

87CS19008

Equipment

Screwdriver

Socket

28

16,

14,

Soldering Iron

i

ng

Eq

u

I

der

W. Saras

does not

or guaranty

and suitability of

these parts have been

to Howard W. Sams

type of replacement part

DATE

& Co.

9-87

Cleaner (non-spray type)

24 and 40

pme nt

Co.

&

P.O. Box 7092, Indianapolis, Indiana

Reproduction or

torial content, in any manner, is prohibited. No patent liability is

assumed with

© 1987 Howard W. Sams &

4300

West

U.S.A.

without express permission, of editorial

use,

the

respect to

62nd

Street, P.O. Box 7092,

of the information contained herein.

use

46206 U.S.A.

Co.

Indianapolis, Indiana

Printed in U.S. of America

or

46206

pic-

MISCELLANEOUS ADJUSTMENTS

POWER

SUPPLY

NOTE:

Do

not operate

the Power

Supply

without

a load.

5V ADJUSTMENT

12V

ADJUSTMENT

NOTE:

Perform

the 5V

Adjustment

first.

Con-

nect the

Input

of a voltmeter

to pin 7

of Con-

nector

SK3-1.

Adjust

the 12V

Adjust

Control

for

a voltage

of 12.0V.

Connect

the

Input

of

a voltmeter

to

pin 9

of

Connector SK3-1

.

Adjust

the

5V

Adjust

Control

(VR1)

for a voltage

of 5.0V.

VR1

VR2

5V

12V

ADJUST

ADJUST

F1

:ib.

CN

(3B)

KEYBOARD

INTERCONNECTING

DIAGRAM

II

PRELIMINARY

SERVICE CHECKS

(Continued)

UAj

v

-^

COMPOSITE

AUDIO VIDEO

RGB

VIDEO

/

*

' * *

\

(

a a

mao

)

B1A1B1

A181Al B1

A1 B1 A1

J10B J10A

J15

J14 J13

J12 J11

J9

S.OV©

1

t

. .

.

(8B)

4.77MHz,N0RMAL

7.16MHz,TURB0

J6

12

U51

B31

A31

B31

A31 B31

A31 B31 A31

831

A31

®

SEE

SWITCHES

S2 AND JUMPERS'"

U41

ROM (1D)

VIDEO SYSTEM (4C)

RAM 128K

v^

U3B

CPU

®

U35

3EU

E4F^lE3

U24

]

P

5

i

SB)

(3C) (BE)

R26A

VOLUME

U22

SYSTEM

BOARD

LIGHT

PEN

*ezz3'.

Y

LOW,NORMAL,

HIGH,TURBO

51

~EJ-

J4

J3

J2

RESET

J8

©

u

J7

33

E6

E5

U55

®

J5

U37

BE

U37A

®]

2A)

BANK

1

BANK

2SBK 25SK

RAM

RAM

SP1

8a Z

*!©

JOYSTICK

PORTS

POWER

SUPPLY

SK3-1

SK3-2

SK2

©

(Ta) VR2

LD

VR1

5V ADJUST

(IB)

F1

v

-'

250V

3A

<J\P

SKI

6C

(£2)

i—n

sv

J2

l§

(SB)

1

s

2 6

J4

12

J9

2

11

J3

1

(SB)

|

6 J5

1

|

m

R1

(£)

U

L

1

4

J7

DISK DRIVE

A

BOTTOM VIEW

SI

-ofo-

_nnnn_

JT

_nnnrL_i

C27J.

i

.001

T

!

+

•Ve

_nnnn_i_

C28l

.001 T

120VAC

@

380BA

J1

11

2

U

r^?

i:

J2

S§

6B

1

s

2 S

J4

12

J9

2

11

J3

1

TP8Q

I

6

J5

1

1

R1

(Si

L_r

1

4

J7

DISK DRIVE

B

BOTTOM VIEW

TANDY

MODEL

1000SX

INTERCONNECTING

DIAGRAM

PRELIMINARY

SERVICE

CHECKS

(Continued)

LOW.

NORMAL

HIGH, TURBO

J4

R26A

J1

RAM

RAM

BANK1

BANKO

VI

III

PRELIMINARY

SERVICE

SERVICE

CHECKS

CHECKS

(Continued)

MATCH THE

THE

©

©

©

NUMBERS ON THE

NUMBERS

COMPUTER DEAD

(A) Check for

pin

tor J6 on

voltages are correct, go to

(D).

rect, check the adjustment of the

5V Adjust (VR1) and 12.0V Adjust

(VR2) Controls on the

Board,

ments."

(B) If the voltages are

nector

and disconnect the power connectors

from

Drive.

5.0V Source (pin 1 of Connector

and

(Pin 9 of Connector

Operating the

a load

Power Supply On and

voltages.

still

(C) If the correct voltages return, re-

connect the

System Board and Disk

a time until the Board or Drive

that
shutdown

sure

when connecting to the System Board

ON THE SERVICE

5.0V

8

and 12.0V at pin

the voltages are not cor-

If

see "Mi seel laneous Adjust-

J6, turn the Computer Off

the System Board and Disk

Connect a

#93 lamp to the 12.0V Source

a

may damage

missing, check

causing the Power

is

Power

at pin

the System

#1129 lamp

Power

the voltages are

If

Power

found. WARNING: Be

is

supply is

INTERCONNECTING

CHECKS TO

-12.0V

1,

9

of Connec-

Board.

Power

missing

J6). WARNING:

Supply without

it. Turn the

Fuse F1

Supply

Drives

If the

part

Supply

at Con-

to the

recheck

to the

one at

Supply to

turned Off

J6)

the

or Disk Drive.

(D)

Check the

(U41) by

SYSTEM BOARD

(A)

KEYBOARD

(A)

(B) Check the Keyboard cable and check

(C)

program runs for a while, then

A

suddenly stops or becomes

in operation. Check RAM

and

1 (IC's

Keyboard dead. Check Connector J4

on the System

tions.

Connector CN on the Keyboard for

good connections.

Check IC U22

substitution.

CPU

substitution.

IC (U36)

U1 thru U16).

Board

on the System Board by

good connec-

for

and ROM IC

erratic

Banks

IC

at

PERFORMED.

BE

(B)

(C)

©

©

©

SOUND

(A) No sound from the Internal Speaker

(B) No sound from the Internal

(C) If

DISK

(A) Disk Drive operation Is

(B) Check

(C) Drive dead. Check for 12V at

CD)

(E) If Switch S2-3

PARALLEL

(A) Paral

DIAGRAM AND

Check Video

tion.

Video display

Check Video

(U24,

IC's

(SP1) and

J10B. Check IC U37A by substitu-

tion.

(SP1).

Volume Control

Board.

Volume Control is set properly,

check Connector

for good

Speaker (SP1) voice coil for conti-

nuity.

DRIVE

Clean

Drive Spindle

Speed

and J9
tor J5

connections.

and 5V

the Drive Board.

are missing, check the Power

ply.

If the voltages are

nector J2, check the setting of

Switch S2-3 on the System Board.

It

IC's U22

Board

Connector J7

the

Check".

Connectors J1, J2, J4 thru

on

on the System Board for

at pin

should

by

PORT

lei

PHOTOS

(U30) by

IC

is

IC (U30) and Video RAM

U31, U34 and U35).

no audio at Connector

Check the setting

substitution.

Port

(R26A) on the System

J1 on System

connections and check

Drive

heads.

Speed, see "Spindle

the Disk

4

of Connector J2 on

set

be

On.

and

is set On,

U37 on the System

does not work, check

for good connections.

WITH

substltu-

not correct.

Speaker

of the

erratic.

Check the

Drive and Connec-

pin

the

If

present

voltages

at Con-

Board

J7

good

1

Sup-

check

VIDEO

(A) No video. Check Connectors J9 and

J10A for good connections and

the

Video cable

itor.

IV

going to

check

the Mon-

(B) Check

IC U55 by

substitution.

NORMAL/TURBO CPU

(D

(A)

PRELIMINARY SERVICE

CLOCK

Run the

the CPU

is pressed:

10 OUT 98,32:PRINT

20

AS=!NKEYS:IF

30 OUT 98,40:PRINT

40 AS=INKEYS:IF

following

clock speed

"NORMAL

AS=""

"TURBO

AS="" THEN 40

program to

each time

THEN 20

switch

(4.77MHz)"

(7.16MHz)"

ELSE 10

CHECKS

key

a

(B)

(Continued)

Check

mal"

set to "Turbo".

not correct,

Check

pin 16

to

speed set

quency does

U51.

for a logic

IC U22

with

and logic High

for

of

"Normal"

check IC

a frequency

IC U51 with

to

Low at

the speed

and

"Turbo". If

not

with

if the

U22.

7.16MHz

switch,

set

of

the

pin 37

to "Nor-

the

reading

4.77MHz

speed

with

the

check

of

speed

is

at

set

the

fre-

IC

DISASSEMBLY

CABINET

Remove

Slide cabinet forward

REAR

Remove three screws from lower rear of rear

panel.

up

DISK DRIVE REMOVAL

Slide

Disk Drive

left front, two

screw from right

Slide

nectors from

from

right side and two screws

Disk

bracket.

POWER

Unplug

Board and Disk Drives.

Remove four screws

Supply
chassis.

REMOVAL

two screws from lower

PANEL REMOVAL

Pull

out

to

clear

metal

tabs on top

on

shield out of

bracket.

screws from

bottom

the Drives forward

rear

Main Chassis.

Drive bracket

SUPPLY

REMOVAL

Power

to chassis

Supply Connectors from

and lift Power Supply

and up

bottom

to remove panel.

Remove

of Disk

of Drives.

Remove

to remove Drives

remove.

to

panel

of

slot on

left

two screws

left rear

Drive

and

unplug

Remove Drives

screws from

four

from left side

Remove rear

from rear holding

front

of cabinet.

and lift

side of

from

and one

bracket.

four con-

of

from

System

panel.

Power

out

of

INSTRUCTIONS

SYSTEM

Remove

four

remove

from

System
System

board

POWER

Remove

remove Fan. Grip

Power

disconnect Connector

chassis with On-Off

Remove

and

KEYBOARD

Remove nine

cabinet

Keyboard

BOARD

REMOVAL

D

i sk Dr

screws

left

holding

side,

System Board.

Board.

of

chassis.

to bottom

Board

out

SUPPLY DISASSEMBLY

four screws

Connector,

screws

four

remove board.

DISASSEMBLY

screws

remove

and

out of cabinet

ves

i

Remove

end

pull

and

Power

left

Supply. Remove

side

of

chassis

Disconnect Speaker

Remove

holding

SKI

Switch

holding

from bottom

bottom

plug- in

four screws

of chassis

Fan.

of

chassis

out

to

remove the end

and

and

board

of

top.

clear the tabs,

AC Connector.

of

cabinet.

and

and

plug

ho

I din

to AC

from

I

and

boards

Unplug

next

to chassis

Keyboard

Lift

of

?f

s
o

m

is,

=;

r-

<

X

SWITCHES

SYSTEM BOARD

VIDEO AND INTERRUPT

S2-1

S2-2 Vertical Sync

S2-3 Floppy Disk Controller

S2-4

Video

Parral

lei

RAM JUMPER

Remove

(U5 thru U8 and U13 thru U16.5

8047 MATH

Remove

IC

jumper from pins El

CO-PROCESSOR JUMPER

jumper from pins E3

(U33).

SWITCHES (S2)

Port

ON

Color

(Internal

CGA Board)

Enab ie Interrupt 5
Enab Ie

Enable Interrupt 7

and

E2 when

and E4 when

AND

Graphics Video

or

optional

I nterrupt

installing

installing

6

JUMPERS

OFF

Optional

Video Board

Disable Interrupt

Disab

Ie

Disable Interrupt

additonal 256K

on 8047

Math Co-Processor

Monochrome

Interrupt

RAM IC's.

5

6

7

PRELIMINARY

SERVICE

CHECKS

(Continued)

LOW.

NORMAL

HIGH, TURBO

J4

R26A

J1

RAM

RAM

BANK1

BANKO

VI

III

PRELIMINARY

ENVIRONMENT

SERVICE CHECKS

(Continued)

PREVENTATIVE MAINTENANCE

Computers perform best in a clean,

dust and smoke
as much as

around the Computer. Do

particles. Even though

commercial Computers

not block cabinet

power devices.

ELECTRICAL

Variations in the line

an AC

devices. A

may be

POWER

voltage can affect the

receptacle that is on a

power-surge protector,

needed to cure the

power line not used by appliances

problem. Do not switch

KEYBOARD

Liquids

Computer

disassemble the Keyboard and

water

cleaner and lint-free wipers

DISK DRIVES

Clean the read/write heads

Use

Handle

Drives can knock

old

spilled into the Keyboard

power plug from AC

and

it dry. Use

let

only an

disk in slot and close

approved head cleaning kit.

carefully

preserve

to

the disk head out

power outlet. Then, if

carefully rinse the

cotton swab to

a

on accessible

of the Disk Drives about

proper disk head alignment. A

door during transport.

cool area that is below 80

home Computers are not affected by

are affected, it is better to

power-line conditioner, or

can ruin it. Immediately

of alignment. If Disk Drive

vents of Computer,

Computer. Try to avoid these

non-interruptable power

power On and Off

after

circuitry or contacts are

Keyboard printed

clean between the keys. Use a

connectors and contacts.

once

month or

a

sudden bump or jolt to

degrees Fahrenheit and

cigarette

maintain a

Monitor, Printer,

or other heavy

spill occurs,

a

smoke-free area

fluctuations by using

current demand

frequently.

disconnect the

contaminated,

circuit board with

non-abrasive contact

must

after

transported,

be

hours usage.

100

free of

smoke

or other

supply

distilled

the Disk

place an

Store disks

handling precautions

in their protective covers

usually found on the back of disk

PRINTERS

Carefully vacuum

cleaner. Do not

blanket. This can cause

a

the Printer regularly. Wipe

oil the machine.

STATIC ELECTRICITY

Static electricity

anti-static

vironment.

discharge can affect

mats, sprays, tools

MONITOR

isolation transformer

Use an

some Monitors use a

the Monitor should never be

pattern is

preserve the

being changed

glare-reduction feature.

HOT chassis

and never touch the disk

surface areas clean using a

The oil will collect

components to

the Computer. In order to

overheat and fail.

abrasive grit and dust. The dust

and materials, and maintain good

with any Monitor that does

(chassis connected to one side

left on for long period of

periodically. Use

time

caution when cleaning

surface. Observe

protective covers.

minimize the

humidity in

not come

high brightness

at

part of the system

as

of the

anti-glare screens, to

light all-purpose

will act as

possibility,

the Computer en-

line). The

AC

level except when

the disk

use

since

face of

VII

r:-fc^ Pi

GH

"

:

SERVICE

"

BOOT UP

Disk

insert a boat*

and turn

le diskette Into

Computer. The

the

On

automatically boot up using

Disk Drive

Operating

A.

System)

puter will display

for a new

date and time.

If

MS-DOS (Microsoft

a

diskette is

the

date

the diskette

used, the

and time

After

Drive

Computer

and

the date and

time have been entered, the version

will

with

ning.

If Function Key

after the Computer beeps when turned On,

Computer will boot

in Drive B.

displayed on the Monitor screen

be
an A

which

indicates the

F3 is pressed immediately

up

from

diskette Inserted

a

DOS

is

MS-DOS

For
the

ENTER

list of file

a

current

key.

Disk Drive,

To specify Disk Drive that is not

current (default),

DIR B:

or

To return

and press

Disk Drive

for

MS-DOS

to

the ENTER

names on

DIR

type

DIR A:

use

8.

from Basic, type SYSTEM

key.

diskette fn

the

and press

for Disk Drive A

>ERATING

A

will

In

Disk

Com-

ask

DOS

of

along

run-

the

the

To load a

Disk Basic

program name enclosed

Enter Key.

To

enclosed

To run

and press the ENTER

press the CTRL and BREAK

the same

able

to prevent the user stopping the program while

RESETTING

CHECKS (Continued)

INS

',-UCTIONS

key or

load Disk Basic. To

type SYSTEM and press

view

To

diskette In the

press the ENTER key.

the

press

Drive B. Type

from Disk
fault)

save a program, type SAVE, the

or not recognize

is running.

it

BASICA

type

a list and the

current Drive, type

ENTER

key

FILES

Drive A If

drive.

program

from the

In quotes, and

program from

a

time. NOTE:

COMPUTER

and press the

return

the ENTER key.

names of

Type

to

list programs

*.*"

"A:

it

Is not the

in Disk Basic

diskette,

in quotes,

press

any Basic

key. To stop

(SCROLL

Some

CTRL and

the

RETURN key

DOS from Basic,

to

programs

FILES

FILES "Bs

from Disk

list

to

current (de-

or

LOAD, the

type

and press the

program name

ENTER key.

the

mode, type RUN

a program,

LOCK) keys at

programs will

BREAK

on a

and

*•*"

and

programs

Advanced

dis-

keys

to

To load
while

in DOS,

(System) program from a

a

the program name and

type

the ENTER key.

blank diskette must

A

can be used

memory. A formatted diskette

DOS

or a Start-up program before the Computer

wll I boot up using

Insert a diskette containing

gram" into

press

on the Monitor screen to

ted diskette.

will wipe out any

on the diskette. The Computer

the

defaults to Disk

Disk

Drive is not

ify the

to be

be

formatted or

ruined

to save information

that diskette.

Disk

ENTER

Drive A. Type

key. Follow

NOTE: Formatting a

programs

Drive A I f

specified. Be sure to spec-

destination Disk Drive

the original diskette may

by the default action.

formatted before

be

which Is

must contain

a "Format Pro-

the instructions

'format the unformat-

previously

automatically

the destination

of the diskette

BASIC

When turned On, the Computer will

MS-DOS

Drive A.
the

The manufacturer

diskette.

DOS.

gram

as long as the MS-DOS diskette

top of the screen.

The version

MS-DOS will

of

also supplies Disk Basic

To load Disk Basic,

Insert

on it. Type

a diskette with Disk Basic

BASIC and press

first boot up

diskette

press

FORMAT

and

diskette

placed

come

up

Is

appear at

pro-

the RETURN

Press the CTRL, ALT, and DEL keys, al

at the same time, to reset the Computer. The

Computer

can also be reset by

Reset button on lower left front panel.

It

CHANGING OPERATING

in

a

The

Video, Disk Drive, and

be changed
F4

immediately after the Computer beeps when

is

it

determine

-

F1

node.

Color

-

F2

Changes the Video mode

-

F3

by

turned On. Use the following chart to

the

Changes the Video mode

Graphics

Swaps Disk

MODES

CPU

pressing

Function Keys

speed

functionofeach Key:

(Computer normally comes up

to

mode.)

TV mode.

to

Drive

references.

becomes Drive B and Drive B becomes Drive

A. The Computer

Drive

top

-

F4

Changes

In
in

puter normal ly comes up with

of

7.16MHz.

(normally Drive

CPU

speed to

boot

will

B).

4.77MHz. The Com-

VOLUME CONTROL

on

Volume

A

Main

ternal

Control

System Board

(R26A)

to set the

is

speaker. The cabinet must

provided on the

volume

to gain access to the control.

three

I

pressing

modes

F1

Monochrome

Drive

from the

up

a CPU speed

the

of

removed

be

the

can

thru

In

A

In-

VII!

PRELIMINARY

SERVICE

CHECKS (Continued)

mk

CHASSIS

BOTTOM

VIEW

HEADS

SPINDLE

CHASSIS TOP VIEW

IX

5j*/M5

x

m

©

o

>-

<

UJ

Q

J_

o

s

COMPL'TERFACTS

SYSTEM BOARD,

KEYBOARD,

MODEL

POWER

TANDY

1000SX

SUPPLY

o

CO

o

C/>

5
o
m
o

SAFETY

Diagram.

Block

Disassembly

General Operating

GridTrace

Power Supply

System

Pinouts

IC

Line Definitions.....

LOgiC

Miscel laneous Adjustments.

Pa

r*T s list.........

Location Guide

Board

ChartS®

PRECAUTIONS

page 1

See

Instructions

Instructions...

Board

and Terminal Gu

a o a s ® e »

. . e .

.......

a

ides.

.30

,.21

th

th

Page

.

41

, 14

.

13

,

29

, 11

.9,40

.

34

ru 33

38

ru 27

INDEX

Photos

Keyboard

Power Supply

System Board 1

Safety

Schematics

Schematic Notes

Switches

Test

Troubleshooting

Precautions

Equipment

Board 28,35

thru

2

and Jumpers

8,

1

37,

2,

0,

42 thru

15 thru

Page

36

39

49
38

38

20

CO

o

1

S-

<

o

o

W
X

14

15

PJPw«

The listing of any available

constitute in any

Howard

by

such replacement part. The

compiled from information furnished to Howard W. Sams & Co.

by the manufacturers of the particular type of

listed.

Sams

W.

4300 West 62nd Street, P.O. Box

replacement

recommendation, warranty or guaranty

case a

& Co. as to

the quality and suitability of

numbers of these parts have been

87CS19008

Howard W. Sams

part herein does not

replacement part

DATE

9-87

Co.

4

Reproduction or

torial

assumed

© 1987

4300

U.S.A.

Indianapolis, Indiana 46206 U.S.A.

7092,

express permission, of

without

content,

with

Howard W.

62nd Street,

West

use,

in any manner,

respect to

is prohibited. No patent liability

of the information contained

the use

Sams

P.O. Box 7092,

Co.

&

editorial or pic-

herein.

Indianapolis, Indiana 46206

Printed in

U.S.

of America

is

TAKEN

WHILE PRESSING

SPACE BAR.

S.OV

50fis

—

ov

J4

X

S.OV

50fis

ov

1

J4

K

t

E

J4

CI

111

33pF^

C1131

33pF^

Y

2

B

J4

7

:

J

^

R

8

D

J4

C1151

33pFl

ciibI

33pF£

CIhI

33pFl

S

FBI

3

J4

.001

T

_L£J

J4

9

S.OV

00

NC

'part of

le

RP3|

10K

10K

f "*

10K

10K 10K

S

T4

10K?

IQtf

CU2i

33pF£

A

PHOTOFACT

STANDARD

NOTATION

SCHEMATIC

WTHgfflna

©

Howard

W. Sams

& Co.1987

TANDY

MODEL 1000SX

100

c

A PHOTOFACT STANDARD NOTATION SCHEMATIC

with

HEH3HH31

© Howard W. Sams & Co. 1987

46

MAC

A

e

IOD=

XMDO

XMD1

XMD2
XMD3
XMD4
XMD5
XMD6

XMD7

YMDO

YMD1

YMD2
YMD3
YMD4
YMD5
YMDS

YMD7

88 1OR

38

10W

MEMR

CS

cc

dt

AOO

AOI

A02

A03

A04

A05

AOS

A07

A08

AOS

AOIO

A011

AOI

2

AOI 3

A014

AOI

5

AOI

6

A017

A018

AOI 9

IODO

I

OD1

I0D2

I0D3

1004

IODS

IODE

I0D7

64

P

S3

P

62

P

61

P

60

P

59

P

SB

P

57

P

56

P

55

P

54

P.

53

P

52

P

SI

?

SO

p

49

P

48

P

47

P

46

P

73

P

72

P

71

P

70

P

6S

P

67

P

66

,83

,84

8040684

U30

©

RP9

33

33

-wv—

77

I

33

|

-=

—wv

J

-

I

5

33

6

|

I

- wv

=*-

43

RP8

33

33

-wv—

33

-WV—

33

-WV—

Si

MAO

MAI

HA2

MAS

MA4

MAS

MAS

MA7

R57

2200

NC

R53J

6.0V IQ

Kf

10)is

|

2

|

OV

S.OVOO

R59

1100

-wv

—

RS8

750

R62

3300

RSO

1200

R61

S80

!

—

W\

—

1.5V

lOfis

2N3904

Q3 VIDEO OUT

R65
270

I,

ns.ov

ci

_C58

£lB0pF

R64
620

,

,

—VA

CI

75

J

-

IOjiF'J'

0176^

.471

78L05A

VR1 RES

£

J10

\>

—

r>

c

C1771

1A

n

470pFj

U

:;R66

r

J10P

28

J10

->

s

2A

J10I

i—

AUDIO—

>

IB

T

Iff

1

JB

S.0VU3

^f

JB

20

33

-wv-

33

-wv-

—

, PART

OF

1

e

RP7

—

—

4l

RAS

CAS

tT

30

31

CA2

MEM

I

OS

MWEO

MWE1

VIDWAIT

mImw

V28MHZ

3

NC-

NC

PART OF

|

RP7

33

I

—wv-

2|

NC

33

-WV—

7

8^

NC

AOO

AOI

1000

1001

1002

1003

I0D4

10D5

1006

1007

NC

NC

38

P

16

PPINT

FDCDACK

PRINTCS

SYSRST

I

OR

IOW

FDCTC

DMATC

TC

27

H

1

H

23

H

31

H

28

H

23

P

30

L

22

P

24

L

25

£

20

if"

40

|1.5V

10fis

OV

8075068

U55

PARALLEL

PORT

ARRAY

10

H

18

IS

e

rpi2

33

12

33

A/W—

13

33

-wv—

14

33

-wv

—

15

33

-wv—

IS

33

-Wv—

10

33

-wv—

33

—wv—

CI64I

.0022±

cissl

.0022±

C166i

.00221

C155i

.0022^

C162J;

.00225

C1B3J-

.00221

C156i

.0022^

9

5j

C167-1

.

.00221

E5 E6

RP1

1 4,™

4700

??

700

4700

4

4700

3

H2 T7

[8

"•

i

I

4700$4700?4700

3

I

m

5.0V00

•

PPDATAO

•

PPDATA1

PPDATA2

•

•

PPDATA3

•

•

PPDATA4

PPDATA5

-

PPDATA6

-

PPDATA7

-

C154i

33pF*

CI

S\X

33pFl

PPACK

PPBUSY-

PPPAEM-

R51<

470K?

CI

53!

33

P

FJ

C1591

33pFJ

C1521

33pFJ

C16oi

33pF$

C16B1

33pFl

PFAULT

PPINIT

PPAUTOF

PSEL

PPSTROB

NC-

J7

3

J7

S

J?

->

7

-J

9

J7

11

J7

->

13

J7

15

J7

17

J7

19

J7

21

J7

4

23

J7

26
J7

30
J?

->

27
J7

25

J7

1

J7

29

PHOTO

CIRCUITRACE

=

SCHEMATIC

CIRCUITRACE

=

CABLING.

TUBE

LINES REDUCE

USE

OF MULTIPLE

LINES

11

=

A

=>D

=100

J7

2

J7

<r

4

J?

<-

6

J7

3

J7

<

10

J7

<

12

J7

<-NC

14

J7

16

J7

18

J7

<^

20

J7

22

J7

24

J7

<— NC

26

J7

<

31

J7

<-

33

J7

<— NC

32
J7

<

34

o

m

&,

r-

S

O

<

o

CO

X

1

R52

4700

1

m

S.0VCA3

A

PHOTOFACT STANDARD

NOTATION

SCHEMATIC

with

EEBHH3B31

©

Howard W. Sams

& Co. 1987

>CA

=CB

=CC

45

3

A

C074HCT02E

PART

0FUS3

RHOTO CIRCUITRACE

=

SCHEMATIC CIRCUITRACE

=

CABLING.

TUBE

LINES REDUCE

USE

OF MULTIPLE

LINES

A PHOTOFACT STANDARD NOTATION SCHEMATIC

w,th

HEHSEHH

© Howard W. Sams

&

Co. 1987

44

I/O CONNECTORS

e

i

< —

.J

m

rpi3

TQK

10K

-WV—

10K

*/w

TOK

^w—

TOK

10K

I

OK

10K

10K

<A29

<{a27

<*A25

<|A24

(A21

<JA20

>.!9

AT

AT 7

ATS

>T5

AT

>13

>T2

A6

I

B2s

BT7

bis

a

4

JT

T, JT2

I

AOO ^A3T

AOT <|a30

A02

A03 <[a28

A04

AOS (A26

A06

A07

A08 <A23

A09 ^A22

ATO

AIT

-A12

-AT

3

-AT 4

-ATS

-ATS

-AT 7

-AT

8

-AT 9

•DO-

•DT

•02-

•

03-

D4-

•D5-

•06-

U

i

I

•

FDCDACK

•NC

•

10

RYDIN

mm

foi

low

memr

—

—

NC

—

—

—

—

-ft

07

DACK3 CBT5

__

-FDCDACK-

-

TJAClcT

REFRESH

<fA9

CAB

-^A7

<f

"I"

<A4

("A3

<JA2

.

I

J13

I

B29>

JT4

|JT5B24V

I-

-

DRQT

-FDCMRQ-

-DRQ3-

T38"-

—

-mEmR-

-mERB-

B30>

B27>-

|

I B20>-

I J

NC

•NC

J

R47

:

R45

2200

R49;

2200'

2200

-<

t

t

OSC
ALE

DMATC

e=

CA

<=

CB

<=

CC

A PHOTOFACT

Howard

©

W.

STANDARD

WiTH

BEBBBBi

Sams

& Co. 1987

NOTATION

SCHEMATIC

P1

J1

380 aA

AC

POLARIZED

*=

Ofra

2SA1441

[7]

Q412V RE6

"~

r

"

MAKEN FOM COMMON TIE POINT

^

PHOTO

CI

RCU]

TRACE

=

SCHEMATIC

CI ROM

TRACE

=

Oj]

COMPUTER

o

c/>

o

(/>

CO

o

m

^

i-

5

o

<

o

CO

X

>

TO

COMPUTER

POWER

SUPPLY

42

A PHOTOFACT

STANDARD NOTATION

SCHEMATIC

©

Howard W. Sams & Co.

1987

POWER

SUPPLY

7

M74LS04P

PART

0FH2

T

C

M
P

u

T
E

R

KEYBOARD

8

HI

5.ovan

SCHEMATIC CIRCUITRACE

A PHOTOFACT STANDARD NOTATION SCHEMATIC

WITH

HESffiEEBl

Howard W. Sams

©

Co. 1987

&

PHOTO

s.ovan

CIRCUITRACE

m

=

=

QT]

IC

PINOUTS &

TERMINAL GUIDES

SN74LS245N

P8068-2

9

10

D1R

W

*cc

d_

J-i G

A1

rv^—4

J

ENABLE

Bl

A2

B2

A3

B3

A4

B4

A5

BS

AS

BS

A7

B7

A8

B8

GN0

^J

U39,U40,U52
TRANSCEIVER

TOP VIEW

(

SN74LS373N

OUTPUT CONTROL

. w

V|

2IDs

OE

o e

a

OE

G

80

3

y

f

v

A

\

r

A

4

20

U

*0E

Q

7Q

S

f

s

3D

30

OE

D

8

a

OE

8

BO

7

\

v

f

¥

f>

K

A

-VI

B

48

"

*8E

a

aE*

°

a

sa

9

<•

\

GrID

^1

ENABL

e e

^1

20

19

IB

17

IB

15

14

13

12

11

U42.U43

LATCH

TOP VIEW

etc VCC

AM

A1S

A13 A1B/53

A12

A17/S4

All

A1B/SS

A10 A19/5B

A9

SSO

AS

NN/HX

AD7

TO

AD6

HOLD

ADS

AD4

NLDA

WR

AD3

io/h

AD2

DVR

AD1 DEN

ADO

ALE

NH1 "iNTA

INTO TEST

CLK

READY

6ND

RESET

(MAX

HUE)

40

39

38

37

3B
35

34

33

32

8087

D8253C-5

C074HCT138E

31

CRO/STO)

30

CR0/ST1)

29

(LOCO

28

CSZ>

27

ran

28 ran
25 caso)

24 casn

23

22

21

U36

CPU

TOP VIEW

P8259A

\J

cs VCC

WR

AO

TO Tnta

D7

IR7

06

1RB

05

1R5

04

IR4

03 IR3

D2

IR2

D1

IR1

DO

1R0

CAS INT

CAS

1 spTen

6N0 CA5

2

U44

INTERRUPT

CONTROLLER

TOP VIEW

SND

VCC

AD14 AD15

AD13

A16/S3

AD12

A17/S4

AD11 A18/SS

AD10 A19/SB

ADS
AD8

aS/s?

Ra/6T1

AD7 INT
AD6

RQ/GTD

AD5

NC

AD4

NC

ADS S2

AD2

si

A01 so

ADO oso

NC

0S1

NC

BUSY

CLK

READY

SND

RESET

KEYBOARD

POWER SUPPLY

\S

1

07 VCC

2 D6

RW

3 05

TO

4

D4 CS

5 03 A1

8 02 AO

7 01

CLK

a DO

0UT2

9 CUM

6ATE2

10

OUTO

CLK1

11

8ATE0 BATE1

12

GND 0UT1

U33

COPROCESSOR

TOP

VIEW

U23

TIMER

TOP

VIEW

HC14529B

STRBX

VCC

XO

STRBY

XI YO

X2 Y1

X3 Y2

A

Y3

B V

GND

Z

U25
INTERFACE
TOP

VIEW

SELECT -<

ENABLE

-<

A

V-—

'

VCC

b-

Y0B

1

C

Y1

62A

Y2

S2B

Y3

81

Y4

Y7

>—

YS

6N0

Y6

V

U19

DECODER

TOP

VIEW

U21,U54,USB,US7

BUFFER

TOP VIEW

DB048C

TO VCC

XTAL 1 T1
XTAL 2

P27

RESET

P2S

SS P25

INT

P24

EA

PI7

TO PI

6

WEN PI 5

WR

PI

4

ALE P13
DBO

PI

2

DB1

P11

DB2 P10
DBS VDD

DB4

PR06

0B5

P23
DBS P22
DB7

P21

SND P20

IC

2C

3C

4C

5

B

7E

314

313

312

311

310

3

9

3 8

6

1

'

°

'

I

DENT

IC

2C

3C

3

8

3

5

3

4

*

IC3

BOTTOM

VIEW

on

I

60

IC2

FRONT VIEW

PHC2

TOP VIEW

M2

TOP

VIEW

E C B

^3

Q2.Q3

BOTTOM VIEW

in

!C

3

4

33

O

I

DENT

PHC1

TOP VIEW

BCE

04

FRONT

VIEW

M1

KEYBOARD

CONTROLLER

TOP VIEW

—

<i

o

u u

u

BCE

Q1

FRONT VIEW

KM412S6-15

AB

"*

SND

D IN
WE

CAS

D

OUT

RAS AB

AO A3

A2 A4

A1

A5

VCC

A7

U1

THRU

U16

RAM

TOP

VIEW

ic

2C
3C

AC

sc

sc
7C
BC
BC

IOC

11C
12C

13C

14C

328
327
326

325
324

323

322

321

320
319
318
317

316
315

IC
2C
3C

(C
SC
SC

7C
BC

31S

315

314

313
312

311

310

39

U37A.U50

TOP

VIEW

U41

TOP VIEW

6 I

VR1

BOTTOM

VIEW

ic

2C

3C

4C

5C

BC

7C
BC
9C

318
317
316
315

314

313

312

311

310

IC

2C
3C
4C

SET

6C

7C

ac

sc

10C

11C

12C
13C

14C
15C

16C

17C

18C
19C

20

C

340
339
338
337
336

335

334

333

332

331

330

329
328
327
326
325

324
323
322

321

IC

320

2C

319

3C 318
4C

317

513

316

Sti

315

7C 314

Bq

313

9C

ai2

on

tin

IC

2C
3C
4C

5C

6C
7C

14

13

312

311

310

3

9

3

8

U18

TOP VIEW

U22,U37,U51,U55

TOP

VIEW

IC

3C

3C

4

3

B

3

7

3 6

S

U24,U31,U34,U35

TOP VIEW

U26.U27.U38.

TOP VIEW

U17,U20,U2B,

U45

THRU

U49,

U53

TOP

VIEW

E B C

Q1.Q3

BOTTOM VIEW

o

C/>

o

CO

o

m

^

"z

o

<

o

CO

X

40

SYSTEM

BOARD

10

3

#

-4**s

.

-

.

:

i^ii'W'iii

afer'li

•'s'R

S: ^ii-

IN?;;

ft

I

I

mm mm

s"&

3*&

j^ci

*"i-

*

A

4 5 6

|

7

J

8

J

9

10

t

11

;

12

J

13

14 15

J

16]17

{

18J19

—

•!

!

MM

S*«.«fci

sis

:<»!»;,:

£U ,€.

.1

<t£ j t.

C)

•-

i>

ft.,

•:

«4£

*i

* **

*

iillll

20 I

21 22

23

A Howard

W.

Sams

EMESSB

Photo

o

o

<

o

c/>

X

SYSTEM BOARD

39

SYSTEM

BOARD

GridTrace LOCATION

GUIDE

C1

C2

C3

C4
C5

C6

C7
C8

C9
CIO

C11

CI 2

C13

C14

C15

C16

C18

C19

C21

C22

C23

C25

C26

C28
C29

C29A

C30

C30A

C31

C32

C34

C35

C37

C37A

C39
C40

C41

C42

C43

C44

C45
C47
C48
C50

C51

C52

C53

C54

C55

C56

C57

C58

C97*

C98*

C99

C100

C101

C102

CI 03

C104

C105
C106

07

CI

C108

CI

09

C110

cm

12

C1

CI 1

14

C1

C115

16

C1
C1

17

C1 18

19

B-1

B-6

B-7

B-8

B-9

B-10

8-1
B-1

D-5

D-6

D-7

D-8

0-9

D-10

D-1!

D-12
E-9
E-12

E-17

E-21

F-22

G-3

G-4

F-6

G-7

1-9

H-12

1-15

H-15

H-17

1-15

1-17

K-5

J -3

J-9

K-9

L-16

K-18

K-20

K-23

L-2

L-5

M-2

M-5

M-7

M-15

0-5

N-15

P-4

P-9

Q-8

Q-11

K-2

M-10

N-11

B-2

A-14

C-17

C-17

C-18
C-18

C-19

C-19

C-19

C-20

A-22

C-21

3

C-21

C-21

C-22
C-22
C-22

B-20

C-15

C1

20

CI

C121

22

CI

C123

24

CI

C125

1

CI 26

C127

C128
C129

C130

C131

CI 32

CI

33

C134

CI 35

C136

C137

C138

C139

C140

C141

C142

CI 43

C144

CHS

46

CI
CI 47
CI 48
CI 49

C150

C151

C152

C153

C154
C155
C156

C157

C157A

C158

C159

C160

C161

C162

63

CI

C164

C165

C166

C167

C168

C169

C170

C171

72

CI

C173
C174
C175

C176

C177

C178

C179

C180

C181

C206

C222

C242
C243
C244

C249

C251

C264

C265

CMC1

D-22

F-1 CR2

F-2 FBI

F-3 FB2
G-3 FB13

CR1

G-4 FB16

F-1 3 FB38

1-2

H-3

F-5

H-3

FB39
FB40

FB41

FB42

C-4 J1

H-19

1-19

J-6

L-11

K-11

K-16

M-7 J8

M-16

M-18

M-20

M-2
P-5

P-9

P-9
P-9

P-10
P-10

P-10

P-11

P-11
P-11

Q-2

0-2

0-3

0-5

0-5

R-7

R-7
0-8
0-2

0-2

0-3

0-4

0-4

Q-4

0-4

0-4

0-5

0-6

J2

J3
J4

J5

J6

J7

J9

J10

J11

2

J12

J13

J14

J15

01

02
03

R1

R2
R3
R4
R6

R7
R8

R9

R10

R11

R12

R13

R14
R15

R16
R17
R18

R19

R20

R21

R22

R23

R-8 R24
R-8

R25

R-9 R26

R-9 R26A

R-9

R-10

R-13

R-14

R-14

S-17 R32
S-17 R33

S-17 R34

S-20

B-1

F-2 R37
L-3

M-1 R39

M-4

R27

R28

R29

R30

R31

R35

R36

R38

R40

N-13 R41

M-2 2 R42

P-13 R43

P-14

R44

R-13 R45

D-1

M-1

B-1 4

B-16

C-20

C-21

R-10
R-10
R-10

R-11

0-13
A-14

A-16

A-18

A-20

N-5

N-11

S-4

S-7

S-10

S-12

R-16

R-17

R-19

R-21

R-23

C-16

D-1

R-14

B-1
B-1 4

C-18

C-18

D-1

D-1 4

D-1
D-1 4

D-1

D-1

D-1

D-1
D-1
D-1

D-20

E-11

F-4

F-4

G-8

G-20

F-22

G-22

G-22

G-6

G-10

F-10

H-2

H-2

H-2

1-2

F-5

H-4

J-10

J-21

J-22

L-7

K-12

M-1 1

N-4

N-6

N-9

N-11

N-11

N-12

N-14

R46

R47

R48

R49
R50

R51

R52

R53

R54

R55

R56

R57

R58

R59

R60

R61

R62

R63
R64

R65

R66

R67

R99

RP1

RP2

RP3

RP4

RP5

RP6

RP7

RP8

RP9

RP10

RP11

RP12

RP13

SI

S2

111

U2

U3

U4

U9

U10

U11

U12

U17
U18

U19
U20

U21

U22

U23

U24
U25
U26
U27

U28
U29

U30

U31

U34

U35

U36
U37
U38
U39

U40

U41

U42

U43

U44

U45
U46

N-15

N-16

0-14

0-14

P-6

0-2

o-i

R-7

R-10
R-10

R-10

R-11

R-11

R-11

R-11

R-11

R-11

R-11

R-12

0-13

R-14

R-15

M-3

C-16

C-16

D-21

H-5

1-5

1-5

H-17

1-16

J-16

M-1

0-3

P-6

P-22

A-21

J -20

A-5

A-6

A-7

A-8

C-5

C-6
C-7

C-8

C-14

E-9

E-11

E-13

E-15

E-17

E-21

H-17

6-1

G-3

G-4

G-5

H-8

H-14

H-15

1-15
1-17

1-19

K-1

K-5

K-7

L-7'

L-13

L-16

L-18

L-20

L-1

L-2

U47

U48

U49

U50

U51

U52

U53

U54

U55

U56

U57

VR1

VR2

Y1

Y2

*

Located

bottom

of

L-4

M-1

M-2

M-4
M-8

M-1 3

0-4

N-13

P-1

P-7

P-9

0-14

S-15

K-10

N-7

on

board.

o

o

CO

CO

2
O
O

m>
o°

o

o

w
X

_,

<

11

5.0V(B)

U10

U11

U53

U51

U56

12.0V(A)

-12.0V

5.0V{A)

SOURCE

SOURCE

SOURCE

NOTE;

ARROWS

ON IC'S

INDICATE

PIN

1

UNLESS

NOTED

2

3

B

C

E

V

R2

mm

VR1

Q3

-5.0V

SOURCE

o

o

"<

SYSTEM

BOARD

12

A

Howard W. Sams

MI:MIIH:MJS

Photo

SYSTEM

BOARD

37

GENERAL OPERATING

BOOT UP

Insert

and turn On the Computer. The Computer will

automatically

Disk

Operating

puter will display

for a new

time

will be

with

ning.

If Function Key F3

after the Computer

Computer will

in Dr

MS-DOS

For
the current

ENTER

current (default),

or DIR

To return

and press the ENTER key.

bootable diskette into Disk Drive A

a

Drive A. If

boot

System) diskette

using the diskette in

up

MS-DOS (Microsoft Disk

a

used, the Com-

is

the date and time and ask

date

and time.

have been entered,

After

the date and

the version

displayed on the Monitor

an A which

indicates the DOS is

is pressed Immediately

beeps when turned On,

boot up

B

i ve

list of file

a

Disk

key. To specify Disk Drive that

B:

Disk Drive B.

for

MS-DOS

to

from a

diskette inserted

names on the diskette in

Drive,

use

DIR A:

type

DIR

and

for Disk Drive A

from Basic, type SYSTEM

DOS

of

screen along

run-

the

the

press

not

is

INSTRUCTIONS

key or type

load Disk Basic. To return to DOS from

type SYSTEM and

To view a

diskette

press the

press the

Drive B. Type FILES "A:

from Disk Drive A

fault)

load

To

Disk

Basic

program

Enter Key.

To

save a program, type

enclosed

To run a

and press the ENTER

press

the

the same time. NOTE: Some programs will dls-^^

able

or not recognize

to

prevent the user stopping the program whilev/J

is

It

running.

RESETTING COMPUTER

BASICA

list and the

in the current Drive, type FILES and

ENTER

ENTER

drive.

program

a

from

and press the RETURN

press the

key. Type

key to list programs

if it is not

ENTER

key.

names

of

FILES

*.*"

to list programs

the current (de-

Disk Basic or Advanced

in

the diskette, type

key to

Basic,

programs on a

*.*"

"B:

from Disk

LOAD,

name enclosed in quotes, and press the

in quotes, and press the

program from

CTRL

and

SAVE,

Basic mode, type

any

key.

To stop a program,

BREAK (SCROLL LOCK)

the

CTRL

program name

the

ENTER key-

keys

and BREAK keys

and

the

RUN

at

J

f\

CO

2*

To

load a (System) program from

while In

the ENTER

A blank diskette must

can be used

memory. A formatted

DOS

wil

insert

gram"

press the ENTER

on the

ted

will

on

defaults

Disk Drive

ify the

to
be ruined

DOS,

type the

key.

be formatted before

to save

information

diskette must contain a

or

a Start-up program before the

boot

I

up

a diskette

into

Monitor

diskette.

wipe out

the diskette.

to Disk

is

destination

be

formatted

by the default action.

that

using

diskette.

containing a "Format

Disk Drive

key. Follow

screen to format the unformat-

NOTE:

any programs previously

The Computer

Drive

not specified. Be

Disk Drive

or

the original diskette may

BASIC

When

turned On, the

MS-DOS

Drive

as long

A.

The version

the top of the

The manufacturer

diskette. To

DOS.

gram on

Insert a diskette

it. Type BASIC and

screen.

Computer will

as the

of

also supplies Disk

load Disk Basic,

program

a diskette

name and press

which is in

Computer

Pro-

A. Type

FORMAT and

the instructions

Formatting a diskette

placed

automatical

A if the

MS-DOS

MS-DOS

destination

come

up in

is

appear at

spec-

sure to

of the diskette

diskette

will

Basic on

with Disk Basic

first boot up

press the

pro-

RETURN

Press the CTRL, ALT, and

at

the same time,

Computer

Reset button

it

can

on

CHANGING OPERAT

The

Video, Disk Drive, and CPU speed modes can

be changed

F4 Immediately

It is turned On. Use the fol lowing chart to

determine

-

F1

mode.

Color

ly

F2

F3

-

-

Changes the

by

the function of each Key:

Changes the Video mode

Graphics

Swaps Disk Drive

to

be reset

also

lower

MODES

ING

pressing Function Keys

after the Computer beeps when

(Computer normal

mode.)

Video mode

becomes Drive B

A. The

top

-

F4

puter

in

of

VOLUME

A

Volume Control (R26A)

Main System Board

ternal

Changes CPU speed to 4.77MHz. The Com-

CONTROL

speaker.

Computer will boot up from the

Drive

(normally Drive

normal

comes up with

ly

7.16MHz.

to set

The

DEL

keys, al I three

reset the Computer. The

left

to

panel.

to

comes up In

ly

TV

mode.

by

front

references.

Drive B

and

is provided on the

becomes

B).

the volume

cabinet must be removed

to gain access to the control.

pressing the

F1

thru

Monochrome

Drive

Drive

CPU speed

a

of the In-

<0

S

O

<

o

o

C/>

X

A

13

CABINET

REMOVAL

DISASSEMBLY

INSTRUCTIONS

SYSTEM

BOARD REMOVAL

Remove

Slide cabinet forward and

two screws from lower front of cabinet.

up to remove.

REAR PANEL REMOVAL

Remove

panel. Pull

three screws

out on bottom

from lower rear

of panel and

up to clear tabs on top to remove panel.

DISK

DRIVE

REMOVAL

Slide

metal

Disk Drive

left

front, two screws from left

screw

Slide the Drives

nectors from

from Main Chassis.

right side and two

Drive

Disk

from

right bottom

shield out

bracket.

forward and unplug

rear

of

Remove

screws from

bracket to

of slot on left side of

Remove two

screws

rear and one

Disk

of

Drives.

Drive bracket.

Remove

four screws from

left

remove

Drives

bracket.

POWER SUPPLY REMOVAL

Unplug Power Supply

Board and Disk

Remove four screws from

Supply

to chassis and lift Power

Connectors from System

Drives. Remove rear

rear holding Power

Supply out

chassis.

SAFETY

rear

of

lift

from

four con-

Drives

side of

from

panel.

of

PRECAUTIONS

Remove

four

remove

from

Disk Drives

screws holding

left side.

System

System Board.
System Board

board

out

of chassis.

POWER

SUPPLY

Remove

four screws

remove Fan.

Power

disconnect

Connector,

Connector

chassis with

Remove

and remove

KEYBOARD

Remove

four screws holding board

board.

DISASSEMBLY

nine

cabinet and

Keyboard

out of cabinet top.

and Power

left side

Disconnect Speaker

Board.

Remove

plug-in boards

Remove four

to bottom

of chassis

DISASSEMBLY

holding Fan.

Grip

end of chassis

pull out to

On-Off Switch

SKI and remove

and AC Connector.

screws from bottom

remove bottom

of cabinet.

Supply.

of

Remove

chassis and

plug

screws holding

from

and lift

Unplug

next to AC

clear

the tabs,

the end of

to chassis

of Keyboard

Lift

and

1.

2. Maintain AC line voltage at rated input.

3.

4. Use

5. Use a grounded-tip, low voltage

6. Use an isolation (times

7. Do not remove or install boards,

8. Do not use freon-propelled sprays. These can

an isolation transformer

Use

Remove

trostatically sensitive devices.

semiconductor

devices can

your

wrist

Computer

AC power from the Computer

"chip" components.

extreme

body by touching a known earth ground.

strap device. This should

caution when handling the printed

be damaged easily by static electricity. Drain off any electrostatic

system AC power On.

for servicing.

Examples of typical

be removed prior

soldering iron.

probe

10)

system before servicing or installing

ES devices are integrated circuits and

circuit boards.

Wear a commercially available discharging

to applying power to the unit under test.

on scope.

floppy disk drives, printers, or other peripherals with

generate electrical charges sufficient

damage semiconductor devices.

9. This Computer system

10. Periodically examine the AC power cord for damaged or cracked

11. The Computer system cabinet is

fit into

must

block, cover, or obstruct these

grounded AC power outlet.

a

is equipped with a grounded three-pronged AC

Do not defeat the AC plug safety feature.

equipped with vents to prevent heat build-up. Never

vents.

elec-

Some semiconductor

charge on

to

plug. This plug

insulation.

12. Instructions

pushed into the vents of the cabinet.

13. Never expose the Computer

place the Computer system near

14

should be given, especially to children, that

This could cause shock or equipment damage.

system to water. If exposed

possible water sources.

objects

to water

should

not be dropped or

turn

the unit Off. Do not

TEST EQUIPMENT

Test

Equipment listed

measurements

by Manufacturer illustrates typical or

is

and

compatible with most

types

used by

equivalent

field

service

equipment

technicians.

used by SAMS' Engineers

to

obtain

TEST EQUIPMENT

Equipment

(COMPUTERFACTS)

OSCILLOSCOPE

LOGIC PROBE
LOGIC PULSER

DIGITAL VOM

ANALOG

VOM

ISOLATION TRANSFORMER

FREQUENCY

COLOR

BAR

GENERATOR

COUNTER

RGB GENERATOR

FUNCTION GENERATOR

HI-VOLTAGE

PROBE

VOM/DMM

Accessory probes

TEMPERATURE

PROBE

CRT ANALYZER

DIGITAL IC TESTER

CAPACITANCE ANALYZER

INDUCTANCE ANALYZER

B & K Precision

Equipment

1570A,1590A,1596

DP51.DP21

DP101.DP31

2830,2806

277,111,116

TR1

10,1604,1653,1655 PR57

1803,1805 FC71.SC61

1211A.1251,

1260,1249

3020,3011,3030

HV-44

PR-28(HV)

TP-28JP-30

467,470

560,550,552

No.

1260,1249 CG25.VA62

Sencore

Equipment No.

SC61

DVM37,DVM56,SC61

HP200

CR70

LC53,LC75,LC76

LC77

LC53,LC75,LC76

LC77

TROUBLESHOOTING

Notes

o

(/>

o

C/)

CO

2

o

2-"

POWER

SUPPLY

NOTE:

a load.

for

the

er

Power

from the System

possible

ages

Power

The Power Supply

Diode

sistor

Power

To determine

down,

03. The

Zener Diode

WARNING:

voltages

further

limiting

supply

when

When

C9 will

it

On.

least

allow the

Do

not operate the Power

A #1129 lamp

the

5.0V Source and

12.0V Source. Use

with a stepdown control

Supply. Disconnect

Board and Disk

damage

to the System from high

that may be produced

Supply.

D11,

Optoisolator PHC2

(03). The

Supply

check for .67V at the

has a

if the

if the

shutdown can

Dl 1 from

Defeating

and currents

damage

AC

shutdown

shutdown

keep the Power

is turned

Turn

to Power Supply.

voltage

power

to the defective Power

Is defeated.

occurs, the

Off

Power

the

stepdown

two minutes

charge

on Capacitor C9

may be used

#93

a

an, Isolation

Supply

when

the

Drives

while

shutdown circuit,

and

circuit

5.0V

Power

be defeated

Source

Shutdown

will

goes

Supply

base

the circuit.

shutdown may

to occur that may do

AC Power Supply

charge on Capacitor

Supply In

and Immediately

Supply

Off and

before turning

to discharge.

without

as a load

lamp

used

for

Transform-

servicing

Power

the

Supply

to avoid

volt-

servicing

Zener

Tran-

shut down the

too high.

is In

of

by removing

Use

shut-

Transistor

allow

a current

high

to

Supply

shutdown

turned

if

back

wait at

It back On to

Power Supply Dead.

open, check for

and

check for

Transistor (01).

power and

put

pins of Diode Dl.

check

SKI. If 120V AC

the

missing,

check for 120V

Coils

L1

collector of

check Diode D1,

check the winding

to pin 6 for

continuity.

check the waveform

Q1.

If the waveform

Check Fuse

possible

a possible shorted Power Amp

If Fuse

and L3, Switch SI and

Is present, check for 163V at

Transistor

on Transformer T1

at the base of Transistor

voltages and components

lator

check

to pin 3 for

No

the winding on

pin 9

tor

and Resistor R25.

No

for 13.3V at the

Transistor

the winding

pin 14

Capacitors C16 and

check Error Amp

itors CI

Control VR2.

Transistor (Q2) and Transistor Q1 and

the winding

on

continuity.

-12.0V

at pin 15

of Connector SK3-1. Check

Transformer T1 from pin 8

for continuity

IC

(IC2),

12.0V at pin 7

and check the

Diode D10,

of Connector

emitter

(Q4).

on

for continuity

C25, Resistors

8,

If

Transformer T1 from pin

CI

IC

(IC3), Transistor

F1. If F1 is

shorts at Diode Dl

F1 is good, apply AC

AC across the AC in-

If

120V AC is missing,

Connector

01

.

If

Thermistor

from pin

163V

If

Is missing, check

is

associated with Oscil-

Transformer

T1

-12V

from pin

Capacitors C23, C24

SK3-1

of the

13.3V is missing,

and check Diode

7.

If 13.3V is present,

12V Regulator

04,

R22 thru R26 and

163V

R1 and

present,

the

to

Regula-

. Check

check

13 to

D8

and

Capac-

<

o

o

CO

X

is

4

2

15

TROUBLESHOOTING

(Continued)

5.0V

No

the

pin

Capacitors

at pin

winding on Transformer T1 from pin

13

for continuity

C19 thru C22 and Coil

MICROPROCESSOR

Microprocessor

for

If the waveform

7.159MHz

a

9

of Connector

and check Diode D9,

(CPU) OPERATION

(U36)

IC

not working. Check

waveform at pin

missing,

Is

SK3-1.

L2.

19

refer to the

"Oscillators and Dividers" section

Troubleshooting

good,

set) of IC U36

The

not correct,
of

reading

check the logic reading

reading should be High when

is turned On,

IC

U51

should be High

turned On,

correct, check

CR2,

Reset

reading

IC

is correct

U51.

OSCILLATORS

Verify Oscillator

ing properly by checking for

nal at pin 27

IC

U51. If

frequency

Module Y1

.

or frequency

guide. If

the waveform checks

at pin

while

then

check the

turning the Computer

Low. If

go

logic reading at pin

the reading is

while turning the Computer On. The

when the Computer Is

then

Switch SI

Low.

go

If the reading is not

Capacitors C134

and Resistor R38. If

at pin

21

and C135, Diode

of IC U51,

AND DIVIDERS

Modules (Y1

16.0MHz

and

the 28.636MHz signal

not

is

If the 16.0MHz

is not correct, check Oscll lator

correct,

and Y2) are work-

28.636MHz

a

signal at pin

is missing or

check

signal

Module Y2.

Check

11

to

IC U36.

of

this

of

21

(Re-

On.

the Computer

21

the

check

sig-

14

of

Oscll lator

missing

is

If the

run

The program

of about

ning, check

If

pulses are

of

U20.

at pin 13

Control is set properly,

the following Basic

10

PRINT

produces a continuous audio

1100

Hertz. While the

for pulses at

pulses are missing,

present,

IC

U20. If

If pulses

of

check IC U51.

for the

IC U37A.

U37A. If

logic

pin 28

not correct,

are

of

check

check

pins 9

waveform

If the waveform is missing, check IC

the waveform Is present, check for a

High

at

IC U22.

of

check IC U22. If the readings

correct,

IC

U47.

IC

for the waveform shown

check for a logic High at pin

If the reading Is not correct,

U47. If the reading

10

and

missing

program:

type In and

CHRS(7): GOTO 10

program

13

pin

check

check

for

pulses at pin

pulses are missing,

is

of IC U19.

IC

U19. If

check IC

are present, check for

IC

U51 . If

If pulses are present, check

shown In Figure

26

pins

If any of the readings are

of IC U25. If the waveform

pulses are missing,

A

at pin

27

and

and logic

Is correct,

Figure A

In

4V

Low

REF

tone

run-

pulses

7

of

at

at

6

2

Is

If

the Oscillator Modules check

the dividers

1.193MHz signal at

14.318MHz

11,

nal at pin

speed mode)

38

pin

If any of the signals are

IC

and 4.0MHz

U51.

In IC U51

pin

3,

signal at pin

7.16MHz

13,

signal at pin

signal

KEYBOARD

Keyboard

Connector J4

CN

on

check

the Connectors

waveforms

the System Board while

on the

check IC

forms

21

2,

trol I er IC

form

Crystal (XL)

waveforms

waveforms

37

and 38 of IC Ml

pulses

are

No

Internal

Volume
set to Maximum

does not function. Check Keyboard

on the System Board

the Keyboard for good

Keyboard

the

at pins 1

Cable for

and cable check

and

pressing

Keyboard. If the

U22

are missing,

thru 24

Is missing

the System

on

check the waveforms

27

and

(Ml) on the Keyboard.

thru

at pin 22, check

and IC Ml. If any

are

missing, check IC Ml.

check good, check for

while

are missing, check IC Ml.

present,

Sound.

check IC M2.

If there Is no

speaker, check the setting

Control

(R26A). The Control

clockwise

by checking for a

8.0MHz

12,

(4.77MHz

16,

at pin

good, check

signal at pin

3. 5795MHz

39

in

signal at

of

500KHz

normal

IC

not correct, check

and Connector

connections and

broken

4

of

wires.

good,

check

Connector J4 on

the Space Bar

waveforms check

Board.

If the wave-

at pins

34

of Keyboard Con-

If

the wave-

6.0MHz

the

of the other

pulses

pressing

If the

at pins

a key. If

If pulses

sound from

of the

should

for Maximum

volume.

sig-

U51

the

good,

the

at

either

is good

shown

In Figure B

waveform

components

waveform

shown

Volume

If the

and

in Figure C at pin

Control R26A

waveform

components associated

waveform

Connector

If

r

r

Figure B

NORMAL/TURBO CPU CLOCK

To check the CPU

type

In and

be

10

20
30
40

98,32: PRINT "NORMAL

OUT

AS=lhKEYS:

OUT 98,40: PRINT "TURBO (7.16MHz)"

AS=INKEYS:

Figure A

pin, check IC U25. If

IC

at

Is missing,

U25, check for the

at pin

1

of IC

check the

the waveform

U26.

voltages

associated with IC U26. If

checks good,

missing,

Is

check for

5

set at

with

the waveform

IC U27 (with

of

Maximum

check the

IC U27. If

checks good, check Capacitor

J1

Speaker SP1

and

r

• 4V

5mSec

REF

•

2V

clock switching circuits,

run

the following program:

H

"

AS=

IF

IF

THEN 20

AS="" THEN 40 ELSE 10

Figure C

(4.77MHz)

waveform

If the

volume).

voltages

CI

H

and

the

the

30,

2V

.

5mSec

2V REF

16

TROUBLESHOOTING

(Continued)

The program changes

a

key

and check for a logic Low at pin 2

quency

pressed. Set

is

4.77MHz

of

set the speed to "Turbo" and

High

at

16

pin

of IC U51. If the readings

rect at

does not switch at

PARALLEL

Para

lei Port

I

J7

for good

pin

pin

PORT

2 and

2,

does not work. Check

connections. If

checks good, disconnect

ed

to Connector J7

the clock speed each time

speed

the

at

pin

16

of IC U51. Then

check for a logic

a frequency of 7.16MHz at

check IC U22. If

pin 16, check IC U51

any equipment

and type

in and

following Basic program:

10 CLS

20

LOCATE

30 OUT

40

PRINT"A=";INP(888)

50 PRINT"B=";(INP(889)
60

PRINT"C=»;INP(890)

70 OUT 888,255:0UT 890,255

80

PRINT"D=";INP(888)

90

PRINT"E=";(INP(889) AND 248)

100 PRINT"F=";INP(890)

110 GOTO 20

The

program

Port

circuits and displays

F) on the

nected to Connector J7,

should appear

1,1

888,0:0UT 890,0

248)

AND

continuously checks the Para I

six numbers (A

Monitor screen.

on the Monitor

With nothing con-

the

following numbers

screen:

A=0

B=88

C=203
D=255

E=88

F=244

"Normal"

to

and a fre-

are not cor-

the frequency

Connector

the connector

connect-

run the

lei

thru

program

The

Monitor

J3

are not being used.

when pin

nected to

J2

or

fol lowing charts to determine

will be.

Connected

To 5.0V

J2-1

J2-2

3-1

J

J3-2

If the numbers are not correct,

lowing checks while the above program is run-

ning.

If pulses are missing, check

pulses

of
U20.

Check for

are present, check

IC

U20. If pulses are missing, check

If pulses are present, check for

at pin

check

for the waveform shown In Figure

IC U17.

IC U53.

Transistors 01 and

tor C1

18

waveform

displays the number

screen when Joystick

The number

1 or 2

5.0V

J3

of Connector

or when pin

connected to ground. Use the

is

4

Connected

Number

244

240

241

242

To Ground

J2-4

J2-6

J3-4
J3-6

pulses at pin

for

10

IC U53. If pulses are missing,

of

If waveform

pulses are present, check^^

If

not correct, check

is

Zener Diode

02,

and Resistors R12, R13 and R14. lf(Q

is

correct,

connect pins 1

Figure

D

240

Connectors

will change

J2

or

or

6

what

J3

Connector

of

the

is

Number

176

112

224

208

make

the fol-

12

IC U19.

of

IC U19. If

pulses at pin

D

at

pin

CR1,

CapacI-«Ji

and

7.0V

OmSec

1

REF

0V

on the

J2 or

con-

number

pulsesC/

4

2 of

8

IC^^

{/J

of

j'

\f)

2

o

o

o

CO

X

<

Make

ing

34-pln

test plug

gram. The

the

paral

a

together

female

Monitor

lei loopback test

pins

17, 19, 21,

edge connector.

to Connect J7

following

screen:

A=0

B=144

C=203

D=255

E=120

F=244

If any of the numbers

for pulses at

program

is running. If

check IC U19.

U55,

Capacitors

C168

and Resistor Packs RP1

15

pin

If pulses

C152 thru C156 and

JOYSTICK PORTS

Joystick

the

Ports

following

10

CLS

20

LOCATE

30

OUT 512,255

40 PRINT

50

GOTO 20

do

not work,

Basic program:

2,2

INPC513)

plug by connect-

23

and run the

numbers

are

of

should appear on

not correct,

IC

U19

while the above

pulses are missing,

are

present, check IC

1 and RP12.

Type in and

and 28

Connect

above pro-

C159

of a

the

check

thru

run

Connectors J2 and J3 to

pulses at pins

2,

1,

pulses are missing, check

ponents

associated

present, check

08

CI

and C109 and Resistor

USING A

If there is a defect In the

Board,

on the Monitor

PRINTER

information

with IC U17. If pulses are

IC U21, Capacitors C104, C105,

DISPLAY

FOR

that is normally

screen may not be visible

5.0V

and check for

13, and

14

IC U17. If

of

the voltages and com-

RP1

Packs

and

CRT Controller

RP2.

displayed

or

readable. In such cases, it may be possible

to send the Monitor

Printer that

Is

While the Computer is in

the Printer

ing the Print

tion

will continue to be printed out until the

output can be

Key. The

Print Key Is pressed again to turn the

Off. It

Is also

the entire screen display by

Key

down and pressing the

Any Basic program that uses

send Information to the Monitor screen

to

be made to send the

by

changing the

PRINT

screen information to

connected to the Computer.

MS-DOS

or

GWBasic,

turned On by press-

Monitor screen

Informa-

Printer

possible to get a printout of

holding the

Shift

Print Key.

PRINT command

the

can

Information

command to

LPRINT.

to a

Printer

a

17

TROUBLESHOOTING (Continued)

VIDEO

No Video. Check waveforms at

11

of IC

check IC U30. If

waveform

(03).

check IC U57,

R59, R61 and R62. If

waveform

waveform is missing,

components

U57.

If any waveforms are missing,

waveforms are good,

at the base of Video Amp Transistor

If waveform

is missing or not correct,

Capacitor C58 and Resistors

waveform

the emitter

at

check

associated with Transistor

pins

of Transistor 03.

is

the

voltages and

VIDEO SYNC

No vertical

tor. Check for a vertical

and

a

If

either waveform

If waveforms

tors

C169 and CI 71 and

Connector J9

No vertical

connected

Check composite

U57. If waveform

If waveform

in waveform at the base of Video Amp

tor (03). If

and Resistor R61

check

R66 and Jack J

VIDEO

HIGHLIGHT

No Highlight. Type

Basic

program:

10

20

30

40 NEXT

50 GOTO

The

program

highlighted

running,

IC U57. If

U30. If

IC

missing at

are present

R54

and Capacitor CI 74.

or horizontal sync

horizontal

are good,

for good

and horizontal

to the

sync waveform at

Is present,

pulses are missing,

Transistor

. If sync pulses are present,

10.

SEG=&HB00

DEF

X=0

FOR

POKE X,

TO

42: POKE X+1,8

X

50

fills the Monitor

characters. While

check for

pulses

pulses are present

pin

16, check IC U57.

at

pin 16, check Resistors

on an

waveform at pin

waveform

is

at

missing,

check

pin

IC U57,

15

check

check pins

connections.

sync on

Composite Video

pin

Is missing, check IC U30.

check for sync

check IC U57

Capacitor CI

03,

4000

In and

STEP

2

77,

run the

the program

pulses at pins 4

are missing

at pin

at pin

COLOR

No color

run

NOTE: Put

line

or some

the following

70.

10

20 SCREEN

30 KEY

40

50 READ

60

70 PRINT

four

DATA

9,

0,1:WIDTH 80

0FF:CLS

FOR Y=1 TO

C:OOL0R 0,C

FOR X=1

»

colors missing.

Baste

program:

spaces between

10,12

3

TO 160

»;

the

80 NEXT X:NEXT Y

90

GOTO 90

2, 6,

good,

03.

RGB

of IC U57.

IC U30.

Capaci-

8

and

a Monitor

Jack (J

11

pulses

Transis-

Resistor

following

screen

and

4,

If pulses

R58 and

Type

in and

quotes In

8

and

check

R57,

check

Moni-

9

10).

of

with

16

check

4

and

The program puts

tal bars on the Monitor

gram is running,

in Figure E

the waveform

13

If

17

of

IC

U57.

Figure E

of

If waveforms

IC U57, check

of

present

pins

forms

IC

at pins

7, 12,

are

good

Resistors R55

itors C58,

C170,

blue, green

screen.

check

at pins 2,

shown

5V

for

6,

In Figure F at pins 7 and

20uSec

REF

0V

are missing at

IC U30.

2, 6,

14

and 18, check IC U57. If wave-

at pins

thru

CI 72

8

7,

R58, R62

and C173.

8, 12,

and

12,

and

While

waveform shown

the

14

Figure F

pin

2, 6,

waveforms

If

13

and missing at

14

and

R63,

and

DISK DRIVE INTERFACE

WARNING: It

Drive to write on

diskette, even If the

tected. Check the Disk Drive

diskette that

ed up on another diskette. Do

Is

possible

for a

defective

or erase Information on a

diskette is write pro-

has programs that have been back-

by first using

not leave the

alignment diskette in the drive while checking

voltages

and waveforms unless

specified In

alignment procedures. The test equipment may

cause the

tions of

diskette

Check a I I setup jumpers and

rect positions

cables

is

of

Disk

Drive circuits to erase sec-

alignment diskette

the

is write protected.

and check all Interconnecting

for good connections.

switches for cor-

WILL NOT READ

Insert

Drive B

the fol lowing Basic program

Drive

a diskette

and

close the door.

running in

10

CLS

20

OUT

30

1014,128:007 1010,33:0UT

OUT 1013,74:S=INP(1012)

containing data In

mode.

read

Type

to keep the

40 OUT 1013,Y:S=INP(1012)

50 FOR

X=1 TO 7

60 S=lhP(1013):S=lhP(1012):PRINT

70

To

NEXT X: LOCATE

80

IF Y=1 THEN Y=5 ELSE

90

operate

GOTO

20

Drive A,

1,1

change

Y=1

line

1014,128:OUT 1010,16:0UT 1010,20.

The program

tor

screen. The

diskette

Drive and

above

program

displays

seven numbers on the Moni-

numbers should change when a

with data on it Is Inserted in the

the Drive door

Is running.

closed while the

red horizon-

the pro-

18

and

and

5V

20uSec

0V

8

13

or

are

check

18,

and Capac-

Disk

the

even If the

Disk

in and run

Disk

1010,37

S

10

to OUT

REF

a

18

TROUBLESHOOTING

If

the numbers do

ing

checks, while the program

a

diskette

pulses at pin 17

(U37). If pulses are missing,

"Index

guide. If

logic Low

IC

check IC

and

readings

pulses at

for

cable. If

refer

the Disk

If

missing

are

pins

missing at

pulses

ing

present

of

U47.

Sensor"

pulses are present,

at pin 1

U48.

If reading

U37.

not correct

are

pins

good connections

the connector and

to the "Disk

Drive Folder.

pulses are present

at pin

present at

19

4,

at pin

IC U47.

and 26

pins

are

present at pins 4

26, check IC U37.

at

pin 26,

If

pulses are

at pins 2 and 7

ing,

check IC U38

pulses are present,

12

of IC U47.

U47.

If

pulses are present,

WILL NOT

Insert

and

lowing

to

upper

number

write

protected

I

f the numbers

"Write

WRITE

a blank diskette

close

the door. Type

Basic

Diskette

the

left corner

should

protected

Diskette

Protect

this Troubleshooting

10 CLS

20 OUT

30

40 OUT

50

60

70 OUT

80 OUT

90 OUT

100

110 PRINT
120

130

140

150 IF

160

NOTE:

diskette

are

not

pin 11

running

pulses are

sor"

section of

1014,

S=INP(1012)

1013,77:S=INP(1012)

OUT

1013,Y:S=INP(1012)

OUT

1013,1 : S= I NP ( 1 01 2

1013,12:S=INP(1012)

101

1013,0:S=INP(1012)

S=INP(1013):S=IN=

FOR X=1

S=INP(1013):S=INP(1012)

NEXT

X:L0CATE

Y=1 THEN

GOTO 20

This

if the diskette

working.

Buffer

of

with

missing,

not change, make

In the Drive. Check

of Floppy

section

Disk Controller

of this

and logic High

is not correct

If reading

at pin

is correct

2,

correct at IC U40,

11

and

pin

30

and

Drive

12, check IC U45.

pin

of IC U37. If

4

or

check

If

pulses

Troubleshooting"

at

pin

check

12,

19, check IC U51

for

are missing,

present, check

of IC U38. If

and

Capacitor CI

check for

If

pulses are missing,

check IC U37.

Into

program

and

of the Monitor

be when

and

change to

is Inserted Into

are

not correct, refer

Does

In and run the

which writes

displays a number

the Diskette

Not function"

guide.

128:0UT

3,1 2:S=I NPC101 2>

1010,33:OUT 1010,37

(1012)

INPH013)

AND 2:S=I NP( 101

TO 5

1,1

Y=5 ELSE

program will

Check

IC

a

blank

Y=1

not write

Index

for Index

U4 while the Drive

diskette Inserted.

refer to the "Index

this

Troubleshooting

the follow-

Is running

for Index

refer

to the

Troubleshooting

check for

at

pin

at

at

check IC U48.

check for

of

Connector J5

check

the Drive

cable check

11

of IC U45

If

for pulses

pulses

19

and

and

If pulses are

pulses at

check

for

pulses are miss-

pulses at pins

33.

check IC

the Disk Drive

continuously

on the

screen. The

2

when a write

is not

the Drive.

to the

section

2)

to the

sensor

circuits

pulses

guide.

with

2

pin

pin

good,

and

pulses

are

.

miss-

pin

pulses

fol-

at

Sen-

(Continued)

While

pulses at pins

Floppy

missing

IC

pulses are present

a I

a

pin

of

1,

pulses at pin 1

1

If

check

pin

pin

in

connections and

connector and

"Disk

Fo

at

WRITE PROTECT DOES

If

Type in and

"Will

ing guide. The

10

ber

IC

screen

ed

if the

If

WARNING:

diskette.

on It

protected

the door.

If

correct, make

blank write

and

Check for

at pin
at pin

good connections

of

If the connector

to the "Disk Drive

Disk

pin 3 of IC U45

check IC U45.

and the

correct,

(U37).

INDEX SENSOR

To

diskette

Type

keep

the

Computer On.

While

at pins

ing at pin

Is

good

If

If

pin

the above

Disk Controller

ing at pins

I readings are

8

of IC U47.

IC

U47. If

ing,

check

for pulses at

pulses

If

If

pulses are

check IC U48.

8,

check

8,

Drive Troubleshooting"

der.

I

Not Write"

on the left

if a diskette

Is Inserted Into

diskette is

that

the numbers

the program running.

4 of IC U45.

3,

Drive

check the Index Detector

in and

the drive running or make all checks

Drive

10

OUT 1014,128:0UT 1010,20:G0T0 10

the Drive

5 and 6

connections

pulses are present at

check IC U45.

6,

program is running,

at pins

25,

4, 19, 25, 30,

4

IC U37.

or

19, check IC U51.

at pins

30 31

or

32, check

4

31

If pulses

and

19

correct, check for

If pulses are missing,

pulses are present, check for

of IC U53. If pulses

IC

U53. If

missing

are

present at pin

22

pin

check the Drive

cable check

NOT

run the program

section

program

upper corner

pulses are present,

9

pins

at pin

If pulses are present at

of Connector J5 for good

8

and

check IC U50.

9,

9

and missing

cable. If the

good, refer

in the Disk Drive

FUNCTION

listed

this

of

will display

Troubles

of the MonitorvJ

that is not write

Drive

the

write

protected.

This
Do

diskette

a logic Low

program also writes

not use

Is Important. Insert

on

the f

protected

a

Into the Drive and

the

Monitor

1 ow

o 1

diskette

at pin

If reading

check pin

and

28

check the

diskette

I

ng

3

Connector J5

of

and the

that has

a blank write

screen are not

checks

in the

and

Is not correct

Drive

and cable check good, refer

Troubleshooting"

Folder. If

reading Is correct at

and not correct

If

number

on the Monitor screen Is not

check the Floppy

reading

correct at

is

Disk Controller

circuits,

Into Drive

A and

close the door.

run the following Basic program

starts running

Is running, check for

of IC U45. If

check pin

5,

and

after turning the

pulses are miss-

8

Connector

of

check the Drive cable.

5 and missing

pin

check

and

32

for

of

are

and miss-

IC U37.

If

If

pulses at

check

are miss-

of IC

U48.

at

to the

under the^}

hoot- fi\

the num-Hr

protect- (A

number

on the

data

close

I

w

th

Drive

logic High

for

cable.

in the

at pin

4,

pin

IC

insert a

to

when

pulses

J5 for

at

2^

fP>

s

o

m>

a

o°

o

o

c/>

X

4

<

19

TROUBLESHOOTING

TRACK

Disk Drive

00, the number should change to the

00

SENSOR

Head

bangs

stop. Type In and run the

program to check

cuits. The program will

00

Track

itor

00.

and display

screen to Indicate the head Is on Track

If the

head Is manually

against the Track

the Track

step

the number

following

00

detector cir-

Baste

the Head back

16

on the Mon-

pushed off Track

number

0.

DRIVE A

10 OUT 1014,128:0UT
20

30 OUT

40 FOR

50 OUT 1014,1

1013,7:S=INP(1012)

OUT

1013,1:S=INP(1012)

T=1 TO 500: NEXT T

28

1010,16:0UT 1010,20

1010,16:0UT 1010,20

:0UT

60 S=INP(1012)

70

80

90 CLSrPRINT INPC1013) AND 16:S=I NPdOl

100 GOTO 40

If the

screen, check

logic Low

Track

On

Track

Off

check

tions and check

are correct, check

IC U45 with the

of

Low with the head Off Track

1013,4:S=INP<1012)

OUT

OUT 1013,2:S=INP(1012)

numbers are

not

(while program is running) for a

9

pin

pin

at

00

and logic High when the head

00.

26

of Connector J 5 for good connec-

of IC

If readings are not

the Drive cable. If readings

for

head On Track

correct

U45

a logic

the Monitor

on

when the

High at

00

00.

If readings

2)

head

correct,

pin

and logic

are not correct, check IC U45. If readings

correct,

are

check

momentary pulses at pin

troller IC (U37). If reading

check

for a

3

logic

readings

readings

IC U37. If

logic High with momentary pulses

IC U46 when the head is On Track

of

Low

when the head Is

are

not correct, check

are correct, check IC U37.

for a

39

of

reading Is

Off Track

logic

High

Floppy Disk

Is not correct,

correct,

check

at pin

00

00.

IC U46. If

with

Con-

and

(Continued)

reading is correct at pin

00

pin
pin

check

4,

4,

IC U49.

check pin

12

connections and check the

connector

to

"Disk Drive Troubleshooting"

and cable check good, refer to the

Folder.

HEAD POSITION

MOTOR

Head position motor not

run the following Basic

continuously alternates

between tracks

00

and

DRIVE B

10 OUT 1014,128:0UT 1010,33:0UT 1010,37

20 OUT 1013,7:S=INP(1012)

30 OUT 1013,1 :S=INP(1012)

40

OUT T=1 TO

50

OUT 1010,37

60

70 OUT

80

Is

is

90

100 GOTO

1013,15:S=INP(1012)

OUT

1013,1

OUT 1013,16:S=INP(1012)

FOR T=1

500:NEXT T

:S=INP(1012)

TO 500:NEXT T

10

While the program Is running, check for pulses

at pins

ler IC

8

U37. If pulses are present, check for pulses

38

37,

(U37). If putss are

and

at pin 11 of IC U46. If pulses are missing,

check IC U46. If pulses are present, check

for pulses at

pulses

are

J5

are missing,

present, check pins

for good connections and check the

pin 4 and

cable. If the connector

refer to the "Disk Drive Troubleshooting" In

Disk Drive

the

If

Folder.

reading

If

Connector J5

of

working,

program,

the

16.

39

of Floppy

check

18

and

3

and not

Is correct at

Drive

cable. If the

the Disk Drive

in

head

Disk

missing,

6

of IC U48. If

IC U48. If

20

and

cable check

correct

for

Type

The

on

check

Connector

of

at

good

and

in

program

Dr I ve

Control-

pulses

Drive

good,

B

IC

DRIVE SELECT AND DRIVE

Drive

A not being selected

Drive B Motors do not turn On. Type

run

following

the

10

OUT 1014,128:OUT 1010,20:GOTO 10

Basic

MOTOR

program:

or

Drive A

and

In and

While the program Is running, check for a

logic

CU22)

are

Low

not correct at pins

U22. If

34

and not correct

U49.

10

and 16

and

check the Drive cable. If the connector

and

cable check good, refer to the "Disk Drive

Troubles

Drive

at pins

and pins

readings are correct at pins

If readings are all correct, check pins

of Connector J5 for good connections

hoot I

ng" in

B

not being selected. Type

2

30

and

at pins

the Disk

and

6

of

34

of Interface IC

IC U49. If

30

or 34, check IC

2

or

6,

Drive

Folder.

in and run

readings

30

check

and

the following Basic program:

10 OUT 1014,128:0UT 1010,37:6OT0 10

While the program is running, check for a

logic

Low

ing Is not correct at pin 3, check IC U22. If

at

pin

3

and

4

of IC U49. If

read-

IC

20

<**

c U

—

co
LU

in

CO

I

I

•*

f<

I

I

LU LU

X

X

^

* *

p"i kn

'fr

°

t

a.

o

-J

•*

co

(O

m in in in

w-x

i

— r— r

GO00CO ON

ON

ON

ON ON

k>

1*1

ki

~xC

>*£

>*£

CO

CO CO

OO
in

\

oo

5

CO22CO

K1

KN

OO

ON

ON

in in

w v

o o

o

o

CO

o

-=r

CN

\r>

o

VO

o

in

*

r~-

no

l

CN

I

LU

*

no

VO

o

ON

o

N

C/>

o

NO
VO
ON

\

CN
ON
in

2

KN

CO

ON
CN

V.

ON
00

KN

2
o

"2-i

O

CO

*.*<*

_l

*—T—«—

KN

I-

CD

O

3

</)

a>

o

z
H

CC

<

Q.

LU

o

CO

UJ
h-

KN

ininin
CDCDCD

poo

UJ

LU LU LU

* * "*

in in

LU

LU

I—

I—

z

z

K^

in
LU
I—

z

00
in

in in

CD

o o

00

in
in

LU LU

t-

z

ON ON

in NO

88

LU LU UJ

ON

ON

•— *-

in in

LU

l-h-

z

z

O

*

(N
fl

\o
no
ON
CD

O

UJ

NO

vO

ON

LU

"z

KN.

ON

CN

O

o

LU

HI

c*

CN

UJ

<

o

o

CO

S

8

SE

.

O

O

>-

2

a

£ cc

S

>-

<

o£

X

o

co

oo

*

_i

•*

o

oo

r»

os:

0_

OSS

CL
=5

CO

or

LU

3:

2

rn

(Y

<r

M

>-
in
>z

i

(5 j>

13 CO

cc

<u

re

O

»

h-

co

O

=

1

a

Q

Z

?

£

O

12

5

CO

Q.

w

OC

H

DC

O

CO

LU

a

i

to

CO
I-

<

a.

O UJ

IQ NO

O

S-sf

•*

O

CO

O CD

>*

>

< in

I

CO CD M

—

in

-3-

•i

KN,

CN

Q

Q

Tt

UlKOIlO

on

—

o_ S

•>*

co

no

<

*

"3"

co com

Q—Q in Q

f-

»

NO 00 ON

Q

oo

in

co

O cn

on _i x

o O

—

o

Q Q Q Q Q

m

co

co

o

—

o a. cn

_i —

s

<OCN

__

to

ro

-*

•>t

< _jr»

—

o

—

_00

X

oo £

CN

<>

S

fc

->

fl

CD

in

N

—

r'N

O

»

«

V—

—

—

I CD

NO CN

«—

K>

in in

CN CN

0-

in in

_j _l cn

S CL. P

KN O

X X

O

—

CL CL O

*

Q

S

CN

5-

CO

h-

kn

00
kn cn

O O

co co

CN CN

^_

oo

ooin^^

ON

1^1

CN

O s

CO

«-

r-

in

r~

*

CN CN

NO

—

—

CN—

Q Q 0< CO

CO CO

CO CO CO

CN CN

CN

CN

on

O

.-

CN

21

CO

z

o

CO

or

V)

Ui
b-

o
z

UJ

>

UJ
s:

o

CO

z
o

UJ

CO

=3

CO

|

CO
or
UJ

>

UJ
s:

o

CO

z

Q

UJ

CO
=>

1

o S

£?

Z

g

a.
oc I

O

ui

K\

"* *

z

> >-

O

z

<<

o o

o

oo

ON

ON

M N

1

1

CM

CM CM CM

—

*—

£S:

tr\

KN.

«— r—

"V.'V

**

in NO NO

00

OO

m^

££

%k

tn

m

88

UJ UJ UJ

££

mtn

CM i<^ »n

h-h-

zz

in

in

in

T 7

* NO 03 NO

OON CM

—

z

T T

o

O

—

ON

•*

so S.

*: CO $£.

in
CM CM

— —
^ st

NO

in O

s:

N^OO

•»

O*o m

—
—

00 CM 00

CO

o

ON
"*

o

*— «^

CM CM

TT

CM

CM

*

•*
io fn
co

-v-s.

ON

in
i^

CO CO to

•*

oo co

CD

OO

*

CO CO
UJ UJ

hl-

z

in

NO

inzi^Q-Ki

cm on

—

lOO NO

i*>.

•«t

s: s:o Q- _i

_joo

><r

*

oo

ON
in

rn r~-1^r- r~- r~ i~

*

t^i

CD

00
IO

———

1—

oooooo

*

z

UJ

ao

o

KN.

—

i

00

ON

in
in

oc in

•—

>•

— *

co

-

HCT

I^ICNIMMin in

O

00 00
"1IOCM CM

K> K-l in

(—

1-t-1—

t-

to

CO

CO CO CO

uj
CM

IO

03

138

HCT

T13

NO

O

^f

-*0

Q^t

T32

O NO

CM

032

O

o

o o

ON CM

N

1

N

2

d

..

*

z

<

•-

o

oc

fiC

<

a.

d

2

a

CC

*»

3

(A

(0

£

§

0)

E

<D

O

«

w-

ex

CD

f

z

o
©

°-.

a>

-g

CC

<B

{Xi

a.

d

ujZ

1-

t-
CC

Z

<

a.

d

d

oc

z

z

2feS!

0-

DC

£=

5

>

<

i- in co

a.

mfi^ m

OOOONIN

»— —

<<

**

————mm CM CM

OOIINIIN'--

in in

\\ OOlOlO

00

<<

NO NO

35 co

<<

—

o o

in m m

O O CD

o

UJ UJ LU

<<

—

o o

in tn tn tn
LU

l-l-l-l-l-l-

Z ZZZ Z Z

in l"l

lACM

(N

Z

—00—

o o o

— —

o

o

l<N

ON

flO\

N — —

1

^"

SI

1 1 1

1

—

»»

•— ^—

n

ON ON ON ON

Nl

—

ww.

03

—

o

—

UJ UJ UJ LU UJ UJ UJ

O

—

NO in

OONO

—•* *

—

K1

m

K"!

Kl

</>&> co

to

ON

ON On

ON

—

—

in CM CM ro

in

—

in —

CD

CD

CD

oooo

UJ UJ UJ UJ

ON ONONON

—

—

m CM

in

—

—

*

OZ<

*o

•*

00

•*

—

—

OONO Z^-OOlO

«*

in rn o >QOtMO- -*

Z.-Z.-

00CM00

—

NO o

OON OO

—

CO

fN f\

ON

ON

o

»

w

(/>

»-

CC c

a.

o

a

q

o

|

I

2

5

§

w

•

S

o

Ui

z

t

<
s

5

h-
co
>-
co

22

—

CM

S 8 2>

CM

o o-

NO

U12

RUU4RUU8RU

X

XX

1-

(-

—

f\

m

=>

Z3

or

X

(—

h-

k>.

r- oo ON

on v

=J DD 3

v— —

—

3 =>

O

CM

3

O

O

z r-

On

H I

£L
DC «5

O

(/)

uj

D
Q

Z

<

C0

-I

(/)

K-

CC

<

a.

%

Q

T>

XI

Z

°:

*

E

5

« o

»

«-

a

?

•o

J5

CO

I-

o

Q

z
o

o

LU

«

V)

0)

c

d)

E

a»

o

Q.

0)

O
O

o

co

z

o

CO
or

ft in

o

ft

—

vo

I-"

o

voftco

o o

tO fO

LU

o

CO

a

LU

CO

3

CO

vO

LU
ft
ft

I

LU

r—

to

inftcm

*-

I

VO

ft

I

CO

r~

o co

ft

VO

O CO ft

O O CO o

ft co

o_

VO

to

o

C/>

o

CO

o
m

£

•z

<

o

o

CO

X

co
CO

o

—

co

o

co

co

to
HI

O

z

•1066

!-•

r- I—

ft

ft

ft
LU LU LU

X X

X

ft

ft

ft

^

f*

ft

<

DC

DC

<

0L

I-

H

K

Z

<

a.

.

o

6

cc

z

z

a.

cc

it

>-

2

<

ft

CM CM CM

COCO

CO

I

I

I

ft ft ff

r-r-~

r»

*:

^.

Loi

co

co

ftftft

ftftft

CM CM

CM

COCO

CO

_J_J _J

ff ft ft

r-

r—

r~-

©O

O

OOO

LULULU

ffftft
ffftft
CMCMCM

CO

CO

CO

_I _J J

ft ft

ff

LULU

LU

Z CD

ft
ft
CM ftftVO

ft

CO ft

CM

_ICM

CO

ft

o

CM

r- _1

Zft

o

co

co co

r—

—

o

OL
CO

O

CO

to

Q-

o

CM

•1066 •1066

to to to

ft

ft ft

UJ LU LU

XXX

CM

I

o in m

to

I

toor-

in

cm in

CO CM

O CO

to

CM

torn

—

CMIft

ft

vo

O O

CO ft

CD CD

0>

cm cm cm
ininin

ft ft

*::*: ^ ^:

cococo

CDCOCO

CM CM

m

ft

OOCDOOC5

oooooo

LU LU LU LU

CD co 03

CMJiOvS

CMCMCM
in in incmcm
ft

LU

hhl-l-l-t-

Z Z

CO

ft

C>

vo

CM CM
in

ft cm

o

ft

—

o^osso

O

CO

3£

2

co

CO

CM

CM

Ov

C0\

—

C\

CJv

CM

CTv

a*

vO

\o

ft

to

to

CO CO

co

CM

CO CO CO

in in

cmcmcm

ft

ft

ONOv01

LU LU

00 CO CO

ft

ft

o\ o

LU LU LU LU LU

ZZZ Z

0v

z

co

in

co

en

in

o in

in tototo

—

CO _l _1C0

tototo

co

CM

WNC4

CO

W*v ft ft ft

CN

o

_ _ _

OV
VO

MNNOOO

to

o\ ct*
CO CO CO CO CO

to
CM
COCOCO
cd

OOO

LU LU

«£

to

CM

cm

CO CO CO

o\

LU

1-1—1-

z z z

CO

I

in

to

VO

o

CO CO O

in

s £

_i _i

CO CO

ooo o o

l_

l_

o\

i

r—

— r--

to

to

CM

CM

co

a

LU

to

to

CM

CM

LU LU

UJ
ft

o

ft ft

vO

I—

CO

O O O

VO IO

XI-

ft

O

o ofto

co or-

l_

CO

O

vO

co

—

-co

MO I ff

in

r--

• ft

ooo

CO ftCOCO

CO

on o—

CM to

23

W

UJ

1-

O
z

CM

CM CM

>*

•*

* **

,

I

z

*~

5

N

2

On

<3\

kn,

K"> KINMA ^

*

-=t

^*

^j-

1

1

LU LU

x XXX XXX XXX

x

in

in in r-

CO CO CO

co CO

co co

•*•*•*

•>* * •* *«*

LU LU LU

t» r-

VO VD

00 CO r~

1*1

*'*•*

«a*

LU UJ LU LU LU

LU

1— «—

V—

UD ooo

(A n^M

**'*

*«*•

Ill

KMOIC1

t— r~

«K1K\

*"*<*

•*

^t -o-

III

LU LU LU

XXX

c

o

OS

H
£

DC fe

LU

Q

(0

_i .=

£

DC

<m

Q.

24

8

S

i

2

S
I

ra

»
«

a

I

c "S

c

5

CO
to

O

H

O

Q
—

9

^s«

LU

CO

</)

(A

0)

o>

E

°-

-

6

a.

d

of

a.

-

V)

o
®

0)

o

1-

H

OC

Z

<

D.

.

d

o

DC

2 Z

MFG

PARTI

2

x

in

5

2

t

o

a.

CD

TYPE

o

< (N

1

in

r-

in

CM

vO

vD
r- r»

o

lOQ^CM^-S-

ja.o<zo a a

>•

=5

CO

1—
D-

vo

CO

*0

O

vO

a\ on

*=* •*

>—

NOvOtWO ON

\o o

a» o

CO

CO 31 Lt_

\o

—

CM CM

in

m in

**>* *!-

CM(NCM cnk>>n

COtOtO

111

•**}

**

r»r-r-

to t6

Co to

in

in

in

*'*'!)•

CM

CM

CM m

tototo tototo VO VO lO

]

f

| _l

•«* «3"

•si"

r~

r-~

r-»

ao o CC

ooo

LULULU

ininin *1

•*

"*

«*

CM CM CM

to to to

to

I I I _l -J

>*

•<*

>t

i^

r— f—

LU LU LU UJ UJ LU

1—

|_

(_

zzz

z z LU

in K~i -a- 00 •*

*

cm in in inojmKin ON

*o

•>« •*

«—

to

_ICM CM OtA

<*

_i<n r~-3-i--

i-~

Z"»- o oo z

o

to 1—

CO

00

*">

fi

ro
1—

r«-

i—

tototo

1

1

1

•"=!•

*f

"=t ooo OO

r— r~

r—

tO to" tr5 lo t^

KN. <<">

fl

r»

r»

r~-

kn

*i

_l

_l

*"**

—

— r

i

CO

C£>

OOO

LU

LU

UJ

t*%

r«"i

i~ r~ r-

kn.

f\ 1*1
to

to
_!

*

•*

st

i— r— i

1-1-

h-

zzz

r-

r-NlflMv

JI^Kl

to

o-*

o

CM

_l

*

o

to

coco

co r-

r-

*•*"*

*—

r—

\-

fc-h-

1^

r~

«—
1— "*

in

<

0\

inwctoio tOiOtOlO lOlDO

cm in

CO

Q.CO

—

o

< CM X t-O

*

r— X cm I~ X CM r- X

-*0

Q

CM O

00 O l~00

„

**

CO

00

»—

r~-

t h- 00 00

—

00

O O O O O O \0 VO

l-V- i-h- h-t-

OOOO

r~

r— r- r~

r~

to

totot^

LU

LU

o

O

1-

OOOQOO

IhOIhO

QtOQ'tO

O r~ co o r-~ oo

*

to t^

"*

•*

r~ r-

*

CM

««

•t
r~

>z

^4

to to

to

•» ^~

v—

•*

*

r— r-

r--

OO

ooo

LU LU

LU

*o \o

»—

w—

1-

1

—

—

. r

• i

UJUJUJ
1—

1—

z z z

Z O

—

—

•*

<t

r»

VO

t

r~
v:

t

CD

\0

^-*

*

1—

U3

*

o

o

co

o

r- r-

KN K*V
=3

<

:z> Z3

co

o\

tn

ia

=3

— CM

"9-

*

=> => Z3 3

•^j-

in vO r— co

*

*

•*

Z> Z3 rs

•*

"si-

S

O a

O

ol
oc

O

(0

UJ

a
a

z
<

h-

tO

_l

W

h-

cc

<

a.

t£

z

to

a

a>

T3

O

5

<D

«

a

£

55

£

§

JO

*r

to

to

cc

o

Q

z
o

S

to

3

CO

CO
CD

a)

E

u

(0

a.

a>

o

o»
a>

co

UJ

O

z

2|

<

of

UJ

o

oc

z

tea

S

<
a

-

— 1— «—

minm

CM CM CM

r»

t-~

r-~

I

I

I

UJ UJ UJ

o

z
t

a.

o

oc

<

a.

o

Z

>•

h

r-. r» f-

-.—.-

** *

r»

r~

^

f- r-- t-»

«??«?

r—

— r-—

r

OCDO

OOO

UJUJ

UJUJ UJ

1-

1-

Z O

r»i-~ O

— —

•*«*

1--1-

in in in

o> o

.-

_ t-

t-

t-

O OO

p~

r~ r~ r»

*£*

^

X

UJ

I-

UJ

in
OS

•-

in

r— h-

o>

—O— Os

X

t-

•*

o »D

X CM

O I~

Q

O

^O

co

r»

o

O

in

00 00 CO

CO

CO

CO

111 1 1 1

KMO

hO K"l

*«**

*

«**

UJ UJ UJ

XXX XXX

in in in

•*•**

CM CM CM CM CM CM

01

COCOCO

1-

in

—

00

-J _l

_l

*

* *

1

—

r—

£0 co

ininin

"3-

•"*

CM

CM CM

COCOCO

1II

•«3-

>*

1

— r— r

"">

00

1

8!

o

OJUJUJ

in in in

*

^r

CM CM

co

co

1II

-*

sf
r~ r~ r—
UJ UJ UJ

t

H-

— t—

z z z

Z

in cm

«*

cm

in in

SO

* *

co

O

IO

_l CM CM X

•* co

in
r^ r- _i cm

o z»•o

co

00

r~

»-

CM

in

in in

=>

r> z>

j-~

co cocoen

sf

*

o

*

CM

co

"S"

o

00

O O O

I-

o

r~

UJ

o

(—

00

•*

r- x

a

o

fi

V—

On

O

o>

r-

r--

i-~ i-~ f~ r-~

fl

C"l

•«*

"*

"fr

1 1 1 i 1 1

UJ UJ UJ UJ UJ UJ CM CM CM

CM

CM

CM

co

co

I-

o

1

— r—

cm

I—

o \o

»

t—

h-

o

cm

O

O

cm

o

00

co

11I

*

*

-a-

r— t-~ t-~

"^

^"

M"
CMCMCM

COCO

CO

I I

I

*

*

"*

p»

r~

r»

CDOCD

OOO

UJ UJ UJ

* * •*

CM CM CM

CO

CO

CO

1 I i

r— r—

r~-

UJ

UJ UJ

z z

•*

-«t

*)

•*

CM
CO

Tf•*ID CO

CM

_l

CM

•* <S>

O in t

CM l~

I-- _J

Z«*O O

co

r— cd co

in

»—

—

OAOlOS

in^m

***

XXX CM CM CM

<

i-

t

*

* «*

CM CM CM

CO

CO

CO

_l

_)

_J

Tj-

Tl-

Tf
r~r—r~

1

coco Jo

•*3-

*}

•*)•

CM

CM

CM

cococo

_l

-J

_1

r~ r— r^

OOO

OOO

UJ UJ UJ

*»

t

-a-

CM CM CM

COCOCO

I I I

***

<*

—

1

-

r—

r--

UJUJUJ

««

*

z

*

<*

00 CM

*

M"

CM CM

_J

O

CO

O

f^ _l CM

-*

O

Z

co

r~. 00

\0

m

in in

*

* *

•**

*

**

000

o>o>o\

NNN

1

1

i

r^

r~

r—

i-~ r» f-

0>

On

O

w\

CMCMCM

VO VO VO
"«

*

"*

K\

t^l

K\

S<£

$£

^

co CO co

1

r—

— r

—

1-

1

•

— r-~

o* o\ o\

000

000

UJ UJ UJ

r~

i-~

r-

1

J

r—

—

ov cr>

cy%

UJUJUJ

(-

(-

I—

z-z

z

1—

m

< 000

in

m co in

CM

O O

Q

J JinSoi

co 00

o o>

r»

r- co

r- co

CM

or

VI

k.

—

l/l

I-

00

—

O"^

°-

b

2f

t

3

C

TJ

«

c

a

«3

O »

£>

e—

—

«3

L,

— >

010

4- —

e

—

y

CO 3 >

-T! < O

-S--8

NOT!

—

>«

T

BO-

*

O

CO 10

1_

t-

0—

—

00 o>

CM

O

O

<•

<m m

OD

00

CO CO

. »

—

C

<

~

C

L

+-

CM

CM

m

3

O

"<

O

o

co

X

z z

z

z

« 8

_l

_J

co a

•

l/l

l/l

>

=

3

in

o

O

*—

>

>-

e

o
o

TJ

(D

ID

_JJ

<

»-

<

z 8

cc

$

•

>

«

•

L.

3e

•

•

3

;

15

•

X

1

I

9

X

.c

a.

tfl

3

$

;

*

x

3

1

T3

«

fc

•

c5

co

25

PARTS

When

LIST

ordering

AND

parts,

state Model, Part

DESCRIPTION

ELECTROLYTIC CAPACITORS

Number, and Description

ITEM

No.

RATING

MAIN

(SYSTEM)

C1

18

.22

CAPACITORS

ITEM

No.

POWER SUPPLY

C1

C2

COILS

LI

L2

L3

T1

RESISTORS

ITEM

No.

ITEM

No.

.1

250VAC

.22 250VAC

&

TRANSFORMERS

Filter

RF Choke
Line Fi

Switching

BOARD

63V 10?

RATING

BOARD

20?

20?

FUNCTION

Iter

(Power and

MFGR.

PART

8393225

XE-224

Special)

RATING

MFGR.

PART

No.

No.

MFGR.

PART

T0-9161-1

PSC-156

T0-4342

No.

ITEM

No.

C99

23

CI

IDENTIFICATION

MFGR.

PART No.

RATING

SYSTEM

39 NPO

330

BOARD

500V

NPO 500V

OTHER

REPLACEMENT

NTE

PART

5%

5%

No.

DATA

PART

8301 332

NOTES

WORKMAN

MFGR.

PART

No.

No.

RU1

R1

R13

RP1

RP2

RP3
RP4

RP5

RP6

RP7

RP8

RP9

RP10

RP11

RP12

RP13

(1) 1000

(2)

10K

(3)

10K

(4)

33

KEYBOARD

Resistor

POWER

NTC 8

SYSTEM

82.

Resistor
Resistor
Resistor

Resistor
Resistor Network
Resistor

Resistor

Resistor
Resistor Network

Resistor

Resistor
Resistor
Resistor Network

5

x

5

x

7

x

4

x

Network

SUPPLY BOARD

Cold

BOARD

5K

\% 1/4W

Network

Network

Network

Network

Network

Network

Network

Network

Network

Network

Metal Film

(5)

150

(6) 4700

(7) 33
(8) 10K

x

x 7

x

8

x

(1)

117-160-45201

160-13

D4FFL160P

8200382

8290210

8290032

8292310
8295033

8295033

8295033
8295033

8295033
8295033

8290016

8292246
8290044
8290010

7

9

(1)

(2)

(3)

(4)

(4)

(4)

(4)
(4)
(4)

(5)

(6)

(7)

(8)

26

PARTS LIST AND

ordering parts,

When

CONTROLS

ITEM

NO.

state

(All

FUNCTION

DESCRIPTION

Part

Model,

wattages 1/2

RESISTANCE

Number,

watt, or

(Continued)

Description

and

less, unless

MFGR.

PART

listed)

NO.

NOTES

SUPPLY

POWER

VR1

VR2

R26A

FUSE

F1

ITEM

NO.

5 Adjust

12V Adjust

SYSTEM

Volume

BOARD

DEVICES

DESCRIPTION

POWER

3 Amp

Fast

SUPPLY

§ 250V

Acting

SPEAKER

SP1

ITEM

No.

3"

SO

PM

8

TYPE

Ohms

MISCELLANEOUS

ITEM

No.

KEY BOARD

PART

NAME

BOARD

2200

2200

1000

MT4 3A

849001

MFGR.

PART

VGEK-PV(1S> 202B

5-222B

H061

VGEK-PV(IS) 202B

5-222B

H061

8279411

DEVICE

250V

REPLACEMENT

MFGR.

PART No.

No.

MFGR.

PART NO.

DATA

QUAM

PART No.

30A05Z8

P#5

HOLDER

722113

™~l

NOTES

NOTES

NOTES

o

Eh

o

o

CO

X

<

L1

L2

SW1

M5

SI

S2

FBI

FB2

FB4

FBI 3

FB38

thru

FB41

Y1

Y2

LED
LED

POWER

Sw i tch

Fan

SYSTEM

Switch
Switch

Ferrite Bead

Ferrlte

Ferrite Bead

Ferrlte Bead

Ferrite Bead

OscI 1 lator

Oscll lator

CABINETS &

Cabinet Top

Rear Panel

SUPPLY

Bead

CABINET

ITEM

8409039 28.63636MHz
8409034

PARTS

(When ordering

PART No.

8719527

8719526

CAPS, Green

Number Lock, Green

Power

Reset

DIP

16MHz

specify

model, chassis

ITEM

&

color)

PART No.

27

LO

tn

§3

•«5f

.

CO

CM

POWER

28

SUPPLY

A Howard W. Sams

HI

•

•

QQ

*c:

;

C3

E3EB3Sffli

i

dr

~M

Immmil ImLmI C3

photo

*zt

oo

CM

POWER

SUPPLY

GridTrace LOCATION

GUIDE

ci

C2

C3

C4

C5

C6

C7

C8
C9

C10

C11

C12

CI 3

CI 4

C15

C16

C17

C18

C19
C20

C21

C22

C23

C24

C25

D1

D2
D3
D4

D5

D6

D7

D8

D9

D10

D11

D13

Fl

IC1

IC2

IC3

L1

L2

PHC1

PHC2

Q1

Q2

03
04

R1

R2

R3

R4

R5

R6

R7

R8

R9

RIO

R11

R12
R13

R14

R15
R16
R17
R18

R19

R20

R21

R22

R23

R24

R25

C-1

E-1

G-2

F-3
G-3

E-3

A-9

F-4

B-11

E-5

B-4

B-6

C-6
F-5

A-13

D-10
C-10

C-1

E-1 1

E-1

E-1 2

E-1

F-12
F-13

C-1

F-1

A-4
E-5
B-4

B-6

F-5

F-5

C-9
E-9

G-11

A-13

F-6

B-1

A-12

F-9

C-1

D-1

D-13

A-11

B-11

C-6

C-8

C-8

B-9

D-1

A-4

C-4

F-6

B-8
B-8
B-6

B-5

G-5

G-5

G-5
E-6

A-10

A-12

A-15

B-1 2

B-1

B-1 2

B-7

B-7

C-1

C-10

C-1

C-1 3

F-13

R26 D-1 2

R27

R28

SKI

SK2 B-1 5
SK3

T1 E-8

VR1 B-1

VR2 C-1 2

2

3

3

3

E-10

B-1 3

A-2

F-1

o

m

>
z

<

o

o

CO

X

29

LOGIC

CHART

SYSTEM

PIN IC IC

NO. U1 U2 U3 U4 U9 U10

1

2 P

3 P P P P P P P

4

5 P

6 P P P P P

7

8

9 P P P P P P

10 P P P P P P

11 P

BOARD

IC

IC IC IC IC IC IC IC IC

P P P P P P P

P P P

P

P

P P P P P P P

P P

P

P P P

P P P

P P P P P

H H H H H H H

P

P P P P

P P P H P

U11 U12 U18

P P P

P

P P

P P L H

12 P P P P P P P

13 P P P P P P P P

14 P

15

P

L L L L L

16

17

18
19

P

P

P

P P P P

P P P

P P P
P P

L L

20

U19 U20 U21

P P P L

P P

H

H L

P P L P

P P

P

P H H

H H

P

P

L

L H L

P P H

L H H

L H

P

H

H H P

H

L

P

H

P

P

P

H

L

H P

L

H L

*

*

IC

H

H

P

H

L

P

P

L

P

L

H

P

H

P

H
H

PIN IC PIN IC PIN IC PIN

NO. U22 NO. U22 NO. U23

1

2

3 H 23 H 3 P 23 P 3
4

5

6

7 P 27

8 P

9

10 P

11 P 31 H 11 H

12

13 P

14 P 34

15 H 35 L 15 P

16 P 36 L 16

17 P 37 H 17

18
19

P 39 L 19 P

20

21 H

L

22 H 2 P 22

H

24

L

L

*

L 4 P

25

H 5 P 5

26 L 6 P

L

28 L 8

P 29

9

L

30 H 10 P

P 32 H 12

33 H 13 P

H

38 L 18 P

H

40

H

H 20 P

1

7 P 7 P L L

14

NO. U23

P 21

24

P

P

L 12

H

L 16

H 17

IC

H 1
H 2

H 4 H

PIN IC IC IC

NO. U24

U25

P H P

L L

L

L

*

P H

6

P L H

8 P

9 H

10 P

11 P H

13 P

14

15

18

P H

P H
L
P

L

L

L P

L

H

H

H

H

U28

P
P
P

L

*

*

*

L

*

H

30

SYSTEM BOARD

LOGIC

CHART

(Continued)

PIN

NO.

1

2

3 P
4

5

H 25

6

P

7

H 27

8

9

H 29

10

P

11 L

*

12

#

13

14

P 34

15

P

16 L

17 P

18 L

19

P 39

20 L

PIN

NO. U30

61 P

62

P

63

P 83

64

P 84

65

P

66

P

67

P

68 P

69

P

70

P

71 P

72

P

73 P

74 P

75

P

76

P

77

P

78 P

79

P

80 P

IC PIN

U29

NO.

L 21 P

P

22
23

L 24

26 H

H 28

30 P

31 P

32

33

35 H 55

36 P

37

38 P

40

IC PIN

NO.

81

82 P 2

IC PIN

U29

NO.

41

H 42 P

P 43

P 44

P

45 P

46

P

47 P 67

P 48

P 49

50 P

51

P

52

P

53 P

P 54

56

P 57

58

P

59

P

60 P

IC

PIN IC

U30

NO.

P

1 P

P

3

P

4

-

5 P

6

7

8

9

10

11

12

13

14 P

15

16

17

18 L

19

20

IC PIN

U29 NO. U29

P 61 P

62

P 63
P 64

65 P

P

66 P

P 68

P

P

P

P

P
P

P

P

P

IC

U33

L

P 22

P

P

P 28

29

P

30

P

31

P 32

P 33

P

34

P

35

P

36

*

37

*

38

PIN

NO.

21

23
24 P 4

25

26
27

U31

P

P P

H

P P
P P
P

H P

P

P
P

P

P
P

L

P 39

L 40

IC PIN

NO. U30

1

P 2 P

P

P

P

3 P 23

P 4

5 P 25

6 P

7

8

9

10

11

12

13

14

15

16 P

17

18

19 P

20 P

IC PIN

U33 NO.

L

P

L 3 P

P
P
P
P

»
*

P

L

P

H 14

P
P

P 17

P 18

P

H 20

IC

PIN

NO. U30

L 21 P

22

P

24

26 H

L

H 29

H 30
L 31 P
L 32

L 33

L 34

L 35

27

H 28 P

36

H 37

H 38 P

39

40

IC IC IC

U34 U35 1136

1 P

2

P

H

5 P

6

P P P

7 P

8 P P

9

H H

10 P

11 P

12 P

13

P P
P

15 P

16 P

P

L

19

PIN

IC

NO.

41

H 42

P 43 L

P 44 P

45

H

46 P

P 47

48 P

H 49
H 50 P

51

L 52 P

H 53

P 54

H 55 P

*

56 P

P

57

58 P

P 59
P 60

P

L 21

P

H

H

P

H P 24

P

P

P

P

P

P

P

P

P P

P P

P

P P 34

H

P

P

P

L

L 37

L

P 38 P

P 39

L 40

IC

U30

L

P

P

P

P

P

P

P

P

P

P

PIN IC

NO.

22
23

25

26

27

28

29 P

30

31

32

33

35 P

36

P

P

U36

L

P
L

P

P
P

P

P

H

P

P

L
H

P

H

S
O

2-i

o

o

CO

X

^

31

SYSTEM BOARD

LOGIC CHART

(Continued)

PIN

NO. U37A

2

3

4 H P

6 H

8

9

20 L

PIN

IC IC PIN IC

U37 NO. U37

P

1

21 P 1 P P P H 21 P 1 P P

L

P P 22 P
P

5 P P

23 P 3 P P P P 23 P 3 P

P

P 4 L P P P

24

25 P 5 L

P 26 H

7

10 P

11 P P

12 P

13

14 P P

15 P P 35 H 15 P

16 H

17

18

19 P 39 L(8)

P 27

H

P

L

L P

P 30 P

P

P P

P 36 K(1)

P 37 L(1)
P 38

28

29

31 P

32 P

33

34

L(3)
L(1)

H(1)

L(4)

L

L(6)

40 H

PIN

IC

PIN IC IC IC IC IC IC

IC

PIN IC

NO. U38 U39

2 P P P P

6

7 P P P P

8 H P P P 28 H

9 P P P 29

10 L

11 P

12 P P P 32

13 P

14 P P L 34

16 P P P 36

17 P P P 37 17 P P

18 P P

19 P P P 19 P P

L

20 H

P

P

IC

IC

U40

P
P

L
P

P

P

H

NO. U44 NO. U44 NO. U45 U46 U47 U48

21

P

1

P 22 H 2 L L(4)

2

H 23 P 3 H L(4)

3

P

4

24

H 1

4 L P

L

*

L(8) L

P

H P H L

L(6) L L

L

HC7) L

H

IC

U41 NO. U41 NO. U42 U43

PIN IC PIN IC IC

22 L

2 P P

P

24 P 4 P P

P 25 P 5 P P
P 26 P

27 P 7 P P

6

8 P

9

P

P

P

P

P

P 30 10 L L

P 31

P 33

P

35 15 P P

P 38

P

U49

H

U50

P

-

11 P P

12 P P

13 P P

14 P

16 P

18 P

20 H

P

P

P

H

P

5 P

6 P

7 P 27 P 7 L

8 P 28 H

9 P

10

11 P

12 L

13 L

14 L

15

16

17 P

18 P

19 L

25 H 5 P H

26 P 6 P P L H(1) L(10) P

8

9

P

10 P P L H<2)

11 P

12 P L(8) P

13 P

P 15

*

14 H H

16 H

20 H

L(4)

H(5)

H

L

L

P P P

H P P

L(1)

LCD

H L(3)

P

H

LCI)

L

L

* *

H H

L(10) P

L

H

H

*
*
*

L

L

P

P
P
P

P
P
P

32

LOGIC

CHART

(Continued)

SYSTEM

PIN IC

NO. U51

H

1

2 H

P

3

4 L

5 L

P

6

P

7

P

8

P

9

H

10

P

11

P

12

P

13

P

14

H

15

P

16

P

17

P 38

18

P

19

20 P

BOARD

PIN

NO.

21 H

22 L
23 P

24 P

25

26

27
28

29

30

31

32

33

34 H

35

36

37

39

40

IC

U51

P

L 6

P

P

P 9

P

P 11
P 12

P

H

H

H 17

P

P

P 20

PIN

NO.

1

2
3

4

5

7

8 P

10 L

13

14

15

16

18

19 P

IC

U52

P

P P

P P

P

P

P

P L

P

P

P

P

P

P

P

P

P

H

IC

IC

U54 U55

U53

P

P H

P L
L
P P

H

*

P

*

P L
P
P

H

P H

P
L L

*

P H

*

H P H

H

P L

P H

P

P H

L

P L

L

H L

IC PIN

NO.

21 H

22 L
23 H

P

24 P

25 L

H

26 H

27

H

28 H

L

29 H

L 30

31 H

32

33

34 P

35

L

36

37

H

38
39

H

40

PIN IC

IC

NO. U57

U55

1

2

3

4

5

6 P

#

7

8

9

10

P

11

P

13

P

P
P 16

P
P
P

20 H

H

P L

H

P

P L

P

P
P

H P

L L

*

12 P

P P
P

14

P

15

P

17 P P
18 H

P L

19

IC

U57

P
P

P

P

P

P

P
P

P

P

L

P

H

KEYBOARD

PIN IC

NO. Ml

»

1

P

2

P

3

4 H

5 H

6 L(1)

7 L

8 P 28

H

9

H

10

P

11

12 H

13 H

14

H
H

15

H

16

17 H

H

18

H

19

20

L

PIN

NO.

21

22

23

IC PIN

Ml

P 1
P 2 L(1)
P

24 P

H

25

26 H 6

P 7

27

P 8

P

29

P

30

P

31

32 P

P

33

34 P

35

L

36 L

37 H(1)

38

H(1)
*

39

40 H

IC

M2

NO.

H(1)

L(1)

3

4 H(1)

5 H(1)

L(1)

L

L(1)

9 H(1)

10 H

L

11

12 H

13 L
14 H

2

O

S-

•z

So

o

o

en

X

1

<•

(1) Probe

Indicates pulse

when

a key

pressed.

is

33

LINE

DEFINITIONS

AAOTHRU AA7 Address

AEN Address Enable

ALE

AUDIO

BBIOR

BBIOW

BREQ

BRESET

BUFDIR Buffer

BUFENB

CAS

Column Address Strobe, Memory

CLK

CLK358 Clock

CLK8M

COL/MNO . .

CPUA08THRU

.Color/Monochrome, Monitor Operating Mode

CPUA19 CPU

CPUADO THRU CPUAD7
CPUCLK

D4CLK

DACK1,

DACK3 Direct Memory Access Acknowledge

DEN Data

DIR

DMA/INTE Direct Memory Access Request/Floppy

Direction, Disk Read/Write Head

DMATC Direct Memory Access

DORCLK

DRQ,DRQ1,DRQ3 Direct Memory Access Request

DS Disk Select

DSA, DSB

ENBNMI Enable

FAST

FDCCHP Floppy

FDCCLK

FDCCS Floppy Disk Controller

FDCDACK Floppy

FDCDMRQ

FDCINT Floppy

Disk Controller DMA Acknowledge

Floppy Disk Controller DMA Request

FDCRST

FDCTC

Floppy Disk Controller

FDCWCK Floppy

IA2 THRU

INDEX Index Sensor

INT

INTA

IOD0 THRU IOD7

IOR

IOW

JOYSTKS

KBDINT

M/IO Select,

MEMIOS

IA7 Interrupt Request Lines 2 Thru 7

Input/Output Data Bits

MEMR

MEMW

Address Latch Enable

Audio Input Signal

Input/Output

Input/Output Write

Read

Bus Request

Reset

Direction

Data

Buffer Enable

Clock Timing Pulses

Clock

Address Bits

08

Thru 19

CPU Data Bits Thru 7

CPU Clock

Clock Pulse, 477MHZ

Enable

Disk

Controller Enable

Terminal Count

Decode Latch Timing Signal

Disk Drive Select A,

Non-Maskable Interrupt

Clock Timing Select

Disk Controller Chip Select

Floppy Disk Controller

Disk Controller Interrupt

Floppy Disk Controller Reset

Terminal Count

Disk Controller Timing Pulse

Interrupt Acknowledge

Input/Output Read

Input/Output Write

Keyboard Interrupt

Distinguishes Memory or I/O

Memory/Input-Output

Clock

Chip

Select

Interrupt

Thru

Joysticks

Select

Memory Read

Memory Write

MOTOR

ON

MTREN

MTREN

MTRON

MWEO Memory

MWE1 Memory

NMI

NMIEN

OSC

OSCOMA

PFAULT

PPACK

PPAUTOF

PPBUSY

PPDATAO THRU

PPI/TIM

PPINIT

PPINT

PPDATA7 . .

Parallel Port Initialize, Set Up

PPPAEM Parallel

PPSTROB

PRINTCS

PSEL

QSO, QS1

Queue

RAS

RDDATA

RDYIN

READ DATA

READY Ready,

B

REFRESH

Current Bus

RESET

RFSH

Refresh Address For Dynamic Memory

RQ/GT

SO, S1, S2

SELECT

SIDE ONE

SIDESEL

SNDCNTLO,

SSO

1,2

Status, Used For Decoding

STEP

SYSRST

TC

TMRINT

TRACK 00

V28MHZ

7

VIDWAIT

VSYNC

WEN

WR

Write, Data Bus

WRDATA

WRITE DATA

WRITE GATE

WRITE PROTECT Disk

WRPAT Write Protect,

Disk Drive Motor

Enable, Floppy Disk

Motor

Motor Enable, Floppy Disk

Motor On, Disk

Write Enable, Bank

Write Enable, Bank

Non-Maskable

Nonmaskable Interrupt Enable

Oscillator Timing 14MHZ

Parallel Port Fault State

Parallel

Parallel Port Automatic Feed

Parallel Port Data Bits Thru 7

Parallel

Provide External Tracking

Status,

Port

Parallel Port Busy

Video Signal Timing

Parallel

Port Paper Empty Sensor

Port Timing Strobe

Row Address Strobe

„

Cycle Is To Be Completed

Refresh Dynamic

Request/Grant,

Function Status

Line Indicates On

Select

Floppy Disk Side One Select

Sound Control Lines

Video System Wait Signal

Info Stored In Memory

Overwrite Protection Sensor

Floppy Disk Side

Timer

Memory Pulses

Characteristics

Current

Stepper

Terminal Count

Interrupt Request

Disk, Track 00 Sensor

Clock Pulse 28MHZ

Overwrite Protection

On

Drive

Interrupt

Oscillator

Acknowlege

Sequence

Interrupt

Port

Chip Select

Port Select

Read Data

Ready

Read Data

Reset

Control

Bus

Line

Status

Select

0, 1,

Cycle

Bus

Motor

System Reset

Vertical Sync

Write Enable

Or I/O

Write Data

Write Data

Write Gate

1

34

o

m

"z

§

fe

<

Howard

A

W. Sam. HIMUHJ&HmI Photo

POWER

SUPPLY

35

o

LU

h-

O

z

00

CO

at

z

=3

a.
LU

i—

o

00

o

z

o

CO

o

QC
<c

ui

r—

o

z

KEYBOARD

36

Howard

A

W. Sam.

wM»|HftjVH|

p

h°'°

5.0V(B)

U10

U11

U53

U51

U56

12.0V(A)

-12.0V

5.0V{A)

SOURCE

SOURCE

SOURCE

NOTE;

ARROWS

ON IC'S

INDICATE

PIN

1

UNLESS

NOTED

2

3

B

C

E

V

R2

mm

VR1

Q3

-5.0V

SOURCE

o

o

"<

SYSTEM

BOARD

12

A

Howard W. Sams

MI:MIIH:MJS

Photo

SYSTEM

BOARD

37

SYSTEM

VIDEO

BOARD

AND INTERRUPT SWITCHES CS2)

SWITCHES AND

JUMPERS

ON

S2-1

Video

Color Graphics Video

(Internal or optional

CGA Board)

S2-2
S2-3 Floppy Disk Control ler
S2-4

RAM

Remove jumper

(U5

8047 MATH

Vertical

Parral lei Port

Sync

JUMPER

from pins

thru U8 and U13

CO-PROCESSOR JUMPER

E1 and E2

thru U16.)

Enable Interrupt 5

Enable

Enable

when instal ling additonal 256K RAM

Remove jumper from pins E3 and E4 when

IC

(U33).

MISCELLANEOUS ADJUSTMENTS

POWER

SUPPLY

NOTE:

a load.

5V

Connect

Connector

(VR1)

Do

not operate

ADJUSTMENT

the

SK3-1.

for

a voltage

^7 Isolated

*—

—

Circuitry not
Circuitry

e

See

+

rrfn

parts list

Ground

Chassis

Logic readings,

taken

Disk
sion

on screen

Diskette

Al I

switches

Voltages

Waveforms

ground, unless

Supply voltage

Input.

Controls

Capacitors

less noted.

Electrolytic

less,

Resistors

noted.

Value

Measurements

less

noted.

the

Input

of a

voltmeter

Adjust

of

5.0V.

ground.

used in some

used In some

voltages

in Power

Drives. No

of compatibility

Up mode. No

keys

along

and Strike

DIP

on

measured

and

Switch S2

with digital

voltages taken

noted

maintained

adjusted

are

for normal

50

volts

capacitors

20% unless

noted.

are I/2W

in ()

used in some

with

switching

Power

the 5V

Supply

to

Adjust

SCHEMATIC

versions

versions

and

diskettes

depressed.

software

with "Insert

Key

any

otherwise.

or less,

when

set On.

meter.

as shown

operation.

or less,

are 50

versions.

as shown,

5% unless

Interrupt 6
Interrupt

Instal ling on

without

pin 9

of

Control

waveforms

in

Ver-

displayed

System

ready".

from

at

un-

5%

volts

or

un-

OFF

Optional

Video Board

Disable

Disable

7

Disable

8047

12V

ADJUSTMENT

NOTE:

nect

the

nector

for a voltage

NOTES

DISK DRIVE

Voltages,

disk

drive interface and

running

shown

not

10 OPEN

20
30 PRINT

40
50 CLOSE
60

NOTE:

protected )

gram.

CD

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

were

moving

FOR X=1 TO

NEXT

GOTO 10

Probe
Probe

H

when

Probe

when

L

Probe

and

Probe

and H

Probe

and

center

Probe

and H

center

Probe
Probe

Probe

Monochrome

Interrupt
Interrupt

Interrupt

Math

Co-Processor

Perform

SK3-1.

the

input

of a voltmeter

Adjust

of

5V Adjustment

12.0V.

INTERFACE AND DISK

waveforms and

following

the

taken when the

unless noted.

SAMS. DAT" FOR OUTPUT

"8:

300

#1,

X

#1

Insert-

"HOWARD

i n

W SAMS"

a formatted

Drive B

Indicates P

indicates

head 1

indicates

head 1

Indicates

L when

indicates

when

indicates

L

when head

of the diskette.

indicates

when

of the

indicates

L when

is selected.

H when

is selected.

H when

off track 00.

L when head

off track

H when

L when

head is

diskette.

H when

Indicates L when

indicates H when

5

6

7

IC's.

the

to

12V Adjust

DRIVE

logic readings

disk drive

Basic

program. Readings

disk drive

AS #1

diskette

before running

when

head

is moving.

head

head

head

00.

head

Is

moving

head

moving

head

is moving.

head

Is moving.

Drive

Motor

first.

pin 7

Con-

of Con-

Control

NOTES

for the

taken while

head

was

(not write

the

pro-

Is selected,

Is

selected,

Is on

Is on track 00

is

out

is

out

track 00

mov

I

ng

from

moving

from

is off.

the

the

In

In

38

SYSTEM

BOARD

10

3

#

-4**s

.

-

.

:

i^ii'W'iii

afer'li

•'s'R

S: ^ii-

IN?;;

ft

I

I

mm mm

s"&

3*&

j^ci

*"i-

*

A

4 5 6

|

7

J

8

J

9

10

t

11

;

12

J

13

14 15

J

16]17

{

18J19

—

•!

!

MM

S*«.«fci

sis

:<»!»;,:

£U ,€.

.1

<t£ j t.

C)

•-

i>

ft.,

•:

«4£

*i

* **

*

iillll

20 I

21 22

23

A Howard

W.

Sams

EMESSB

Photo

o

o

<

o

c/>

X

SYSTEM BOARD

39

IC

PINOUTS

&

TERMINAL

GUIDES

SN74LS245N

P8088-2

9

10

01R

w VCC

H

_^r~] r\_

3-i

S

Al

[^(—4

J

ENABLE

(

rPI

B1

A2

rs7 )

(

3—

M

B3

A3

r^7 (

)

3-^1

B3

A<4

r^

7

/

)

j >p-i

B4

A5

r^v

)

j

>->^

B5

AG

rs7

^

r

r?i

B6

A7

r^r r

1

r r?1

B7

AS

r^

^

Vi

BB

6NC

^J

U39,U40,U52

TRANSCEIVER

TOP VIEW

6ND

kj

vcc

AM

A15

A13

A16/S3

AI2

A17/S4

All A1B/5S

A10 A19/S6

A9

sso

A8

MN/MX

AD7

RD

ADS

HOLD

ADS

AD4

HLDA

WR

AD3

I0/M

AD2 DT/R

AD1 dEn

ADO

ALE

NM1

IN7A

INTR

TEST

cut

READY

sw RESET

(MAX NODE)

40

39

38

37

3E

35

34

33

32

8087

31 CR8/6T0)

30 CR8/6T1)
29 COOO
2B

(52)

27 ran

26

SO)

25 (OSO)

24 CQS1)

23
22

21

SN74LS373N

OUTPUT CONTROL

<fv^

10

ID

^1

2

OE

6

a

0£

G

D

80

3

20

20

V /

f

%

t

("

4

"

«0E

a

a

70

5

60

6D

63030

OE

8

a

e d

7

\

v

e <i

X

t

A

SD

sa

840u

5

0E

a

aE*

°

a

9

4

>s

GfJO

^"1

ENABL

E 6

\l

""

20

19

18

17

16

15

14

13

12

11

U42.U43

LATCH

TOP

VIEW

U36
CPU

TOP VIEW

P8259A

vy

cs

VCC

uS

AO

w> Tnta

D7

1R7

DB 1RB

D5 IRS

D4 1R4

03 IRS

02

IR2

D1 IR1

DO

IRO

CAS INT

CAS

1

SP/EN

6ND CAS

2

U44

INTERRUPT

CONTROLLER

TOP VIEW

SND VCC

AD14 AD1S

AD13

A16/S3

AD12 A17/S4

AD11 A18/S5

AD10 A19/S6

AD9

AD8

WE/S?

P.0/6T1

AD7 INT
AD6 RO/GTD

ADS

NC

AD4

NC

AD3 S2

AD2

si

AD1 so

ADO aso

NC

asi

NC

BUSY

cue READY

SND

RESET

D8253C-S

V-

1

1 07 VCC

2

06 Rjf

3

OS RD

4 04 CS

5

03

Al

6 02 AO

7 01

CLK2

8 DO

0UT2

9 CLKO BATE2

10

OUTO CLIO

11 SATEO

6ATE1

12

OND

0UT1

C074HCT138E

KEYBOARD

POWER SUPPLY

U33

COPROCESSOR

TOP

VIEW

U23

TIMER

TOP VIEW

HC14529B

STRBX

VCC

XO

STRBY

XI

YO
X2 Y1
X3 Y2

A

Y3

B II

GNn

Z

U25

INTERFACE
TOP VIEW

A

>

—

"^

VCC

fl

I

C

5—

Y1

62A Y2

62B Y3

81

Y4

Y7

Y5

GND

Y6

Y

U19

DECODER

TOP

VIEW

SN74LS244N

V

U21,U54,US6,US7

BUFFER

TOP VIEW

D804BC

TO VCC

XTAL 1 T1

XTAL

2 P27

RESET

P26

SS

P25

iSt

P24

EA PI 7

RD

PI6

PSEN PIS
HR PI

4

ALE PI

3

DBO

PI

2

DB1

P11

DB2

P10

DBS VDD

DB4

PR06

DBS P23
DBS

P22

DB7 P21

6N0 P20

IC

2C
3C
(C

SC
6C

7C

314
313
312

311

310

39

3

8

6 1

>

o

,

1DENT

IC

2C
3C

3

6

3

5

3

4

s

1C3

BOTTOM

VIEW

uuu

1 60

IC2

PHC2

TOP VIEW

M2

TOP VIEW

E C B

Q2.Q3

BOTTOM

VIEW

FRONT

VIEW

3

4

2C 3

3

O

1IDENT

PHC1

TOP

VIEW

BCE

Q4

FRONT VIEW

M1

KEYBOARD

CONTROLLER

TOP VIEW

A

^,

UUU

BCE

Ql

DNT

VIEW

KM41256-15

AS

"'

6ND

D IN

UE

CAS

D OUT

RAS A6

AO A3
A2 A4

A1 A5

VCC

A7

o

c/>

o

(/>

CO

o

z

o

<

©
X

U1

THRU

U16

RAM

TOP VIEW

IC

28

21= 327

3d

026

4C

32S

SC

324

6C

323

7C S322

sp

C321

9C

b20

IOC

Pl9

11C

ai8

12C 317
13C =316
14C =315

U41

TOP VIEW

IC

2C

3C

4C

5C
6C
7C
BC

316
315

3H

313

312

311

310

39

U37A.U50

TOP VIEW

6

I

VR1

BOTTOM

VIEW

ic

2C

3C

4C

5C

6C
7C
8C
9C

318
317
316
315

314

313
312

311

310

IC

2C

3CI

4C
SC

6C

7CT

SC

9C

IOC

11C

12C
13C

14C

ISC

ISC
17C

1BC
I9C

20

C

340

339
33B
337
336

335

334

333
332

331

330

329

328

327

326
325

324
323
322

321

IC

320

2C

319

3C

318

4G

317

SC

316

6C

pis

7C

314

8C 313
9C

p12

IOC 311

U18

TOP VIEW

IC

314

2p

313

3C| 312

4C

an

5p

310

SO

3

9

7C 3 8

U17,U20,U28

U45

THRU

U49

US3

TOP VIEW

U22,U37,U51,U55

TOP VIEW

ic

2C
3C

4C

3

6

3

7

3 6
3

5

U24,U31,U34,U35

TOP

VIEW

U26,U27,U38

TOP VIEW

E B C

Q1.Q3

BOTTOM VIEW

40

S 1
S

>

U1

2

O

P>

<

o

o

w

,

£

-•

1-

BLOCK

DIAGRAM

41

PI

J1

380 «A

AC

POLARIZED

*=0

Ofw3

12.0V

2SA1441

rn

Q412V

RE6

*~

A7AKEN FOM

COMMON

TIE POINT

PHOTO

CI

RCU]

TRACE

=

SCHEMATIC C1RCU1

TRACE

=

[TT|

TO

COMPUTER

POWER

SUPPLY

42

A

PHOTOFACT STANDARD

NOTATION SCHEMATIC

with

raronnrcra

© Howard W. Sams &

Co. 1987

POWER

SUPPLY

7

T

P

w
E

R

S

U
P
P

L
Y

JB

J6

<^

J6

2

JB

JG

C264

1

I

C110

=

.01

ci66,ciia

CI

51, CI S7,

22(iF

C143,C144±

''I

C4Q.C131

C132,C136

.47

,C126J

,C18lT

C39_

r

C45T CS"?

C57

CI

SO

M44T

*

C145J

22MF1

220pFT

.0022

TRACE

r

I

*

C12S1C242

C142T

1*

=

=

Ml

C47 THRU

11

C37A,

THRU

CI

49,

THRU

C249,C251T

C2B5.C9B

C26S,CSS

.0022

PHOTO

SCHEMATIC

1

na nq r^QAi

CZ1 THRU

CZa

.11

FBI

CIRCUITRACE

CIRCU I

C25,C26,C30A.

C

34,C35,C37

.1

CI

THRU

37

C157A.C158'

.001

-$"

C1011

.001"

VR2

VOLT

T

79M0SCT

RE6

PHOTO

SCHEMATIC

CIRCUITRACE

CIRCUITRACE

C148J
22MF1

=

=

C180,C146,C147.

C17S

10|jF*

C17B_

a

11

r

'i

.IT

-ta

S

:

SS.OVCA]

mS.0V<B3

-a

m

12.0V U3

SOURCE

5.0VMS

I SOURCE

I

SOURCE

SOURCE

-12.0V

SOURCE

-s.ov

SOURCE

O

a
m

>
z

a

o

<

o

o

CO

x

43

3

A

C074HCT02E

PART

0FUS3

RHOTO CIRCUITRACE

=

SCHEMATIC CIRCUITRACE

=

CABLING.

TUBE

LINES REDUCE

USE

OF MULTIPLE

LINES

A PHOTOFACT STANDARD NOTATION SCHEMATIC

w,th

HEHSEHH

© Howard W. Sams

&

Co. 1987

44

MAC

A

e

IOD=

XMDO

XMD1

XMD2
XMD3
XMD4
XMD5
XMD6

XMD7

YMDO

YMD1

YMD2
YMD3
YMD4
YMD5
YMDS

YMD7

88 1OR

38

10W

MEMR

CS

cc

dt

AOO

AOI

A02

A03

A04

A05

AOS

A07

A08

AOS

AOIO

A011

AOI

2

AOI 3

A014

AOI

5

AOI

6

A017

A018

AOI 9

IODO

I

OD1

I0D2

I0D3

1004

IODS

IODE

I0D7

64

P

S3

P

62

P

61

P

60

P

59

P

SB

P

57

P

56

P

55

P

54

P.

53

P

52

P

SI

?

SO

p

49

P

48

P

47

P

46

P

73

P

72

P

71

P

70

P

6S

P

67

P

66

,83

,84

8040684

U30

©

RP9

33

33

-wv—

77

I

33

|

-=

—wv

J

-

I

5

33

6

|

I

- wv

=*-

43

RP8

33

33

-wv—

33

-WV—

33

-WV—

Si

MAO

MAI

HA2

MAS

MA4

MAS

MAS

MA7

R57

2200

NC

R53J

6.0V IQ

Kf

10)is

|

2

|

OV

S.OVOO

R59

1100

-wv

—

RS8

750

R62

3300

RSO

1200

R61

S80

!

—

W\

—

1.5V

lOfis

2N3904

Q3 VIDEO OUT

R65

270

I,

ns.ov

ci

_C58

£lB0pF

R64
620

,

,

—VA

CI

75

J

-

IOjiF'J'

0176^

.471

78L05A

VR1 RES

£

J10

\>

—

r>

c

C1771

1A

n

470pFj

U

:;R66

r

J10P

28

J10

->

s

2A

J10I

i—

AUDIO—

>

IB

T

Iff

1

JB

S.0VU3

^f

JB

20

33

-wv-

33

-wv-

—

, PART

OF

1

e

RP7

—

—

4l

RAS

CAS

tT

30

31

CA2

MEM

I

OS

MWEO

MWE1

VIDWAIT

mImw

V28MHZ

3

NC-

NC

PART OF

|

RP7

33

I

—wv-

2|

NC

33

-WV—

7

8^

NC

AOO

AOI

1000

1001

1002

1003

I0D4

10D5

1006

1007

NC

NC

38

P

16

PPINT

FDCDACK

PRINTCS

SYSRST

I

OR

IOW

FDCTC

DMATC

TC

27

H

1

H

23

H

31

H

28

H

23

P

30

L

22

P

24

L

25

£

20

if"

40

|1.5V

10fis

OV

8075068

U55

PARALLEL

PORT

ARRAY

10

H

18

IS

e

rpi2

33

12

33

A/W—

13

33

-wv—

14

33

-wv

—

15

33

-wv—

IS

33

-Wv—

10

33

-wv—

33

—wv—

CI64I

.0022±

cissl

.0022±

C166i

.00221

C155i

.0022^

C162J;

.00225

C1B3J-

.00221

C156i

.0022^

9

5j

C167-1

.

.00221

E5 E6

RP1

1 4,™

4700

??

700

4700

4

4700

3

H2 T7

[8

"•

i

I

4700$4700?4700

3

I

m

5.0V00

•

PPDATAO

•

PPDATA1

PPDATA2

•

•

PPDATA3

•

•

PPDATA4

PPDATA5

-

PPDATA6

-

PPDATA7

-

C154i

33pF*

CI

S\X

33pFl

PPACK

PPBUSY-

PPPAEM-

R51<

470K?

CI

53!

33

P

FJ

C1591

33pFJ

C1521

33pFJ

C16oi

33pF$

C16B1

33pFl

PFAULT

PPINIT

PPAUTOF

PSEL

PPSTROB

NC-

J7

3

J7

S

J?

->

7

-J

9

J7

11

J7

->

13

J7

15

J7

17

J7

19

J7

21

J7

4

23

J7

26
J7

30
J?

->

27
J7

25

J7

1

J7

29

PHOTO

CIRCUITRACE

=

SCHEMATIC

CIRCUITRACE

=

CABLING.

TUBE

LINES REDUCE

USE

OF MULTIPLE

LINES

11

=

A

=>D

=100

J7

2

J7

<r

4

J?

<-

6

J7

3

J7

<

10

J7

<

12

J7

<-NC

14

J7

16

J7

18

J7

<^

20

J7

22

J7

24

J7

<— NC

26

J7

<

31

J7

<-

33

J7

<— NC

32
J7

<

34

o

m

&,

r-

S

O

<

o

CO

X

1

R52

4700

1

m

S.0VCA3

A

PHOTOFACT STANDARD

NOTATION

SCHEMATIC

with

EEBHH3B31

©

Howard W. Sams

& Co. 1987

>CA

=CB

=CC

45

100

c

A PHOTOFACT STANDARD NOTATION SCHEMATIC

with

HEH3HH31

© Howard W. Sams & Co. 1987

46

MOD

Si

X
w

Q

°

o

CO

O

CO

o

A PHOTOFACT STANDARDNOTATION

SCHEMATIC

WITH

©

Howard

W.

Sams

&

Co. 1987

TANDY

MODEL

1000SX

47

4U

m

AMS

S

x
w

o

o

>

o

a

_J

UJ

Q

O

CD

CO

O

CO

o

COMPUTERFACTS"

GrIdTrace

Main Board..

IC

Pinouts

i-OCJ I C 0n3l r

rSPTS

Location

and Terminal

• ••»•*••••••••••«••**

L. t ST» ••«•«•••••«•••••«••<

Guide

Guides..

Page

.10,11

.. 15

..

.7,8,9

INDEX

15

Photos

Chassis-Bottom

Chassis-Top View..

Index

Board

Main Board

Schematic. • .

Schematic Notes

Troub leshoot

Ing

Vie

TANDY

MODEL 1000SX

DISK

Page

..

16

..

14

..

13

••6,12

2

.. 9

.3,4,5

DRIVE

o

c/>

o

CO

CO

3

O

Oh

m

to

•z

<

o

o
w
X

Howard

3y^wi«#Ti

The listing

constitute

by Howard W. Sams

such replacement part. The

compiled from information

by the manufacturers

listed

f

m

4300 West 62nd Street,

of any available replacement part herein

in any

recommendation, warranty

case a

& Co. as to

of the particular type of replacement part

the

quality and suitability of

numbers of these parts have been

furnished

87CS19008

Howard

to

W. Sams 1 Co.

P.O. Box 7092, Indianapolis,

not

does

or guaranty

W. Sams & Co.

9-87

DATE

Reproduction

torial

assumed with respect to the

© 1987 Howard W.

4300

U.S.A.

Indiana 46206 U.S.

or use, without express

content, in any manner, is prohibited. No patent liability is

62nd Street, P.O. Box

West

Sams

permission, of

of the information contained herein.

use

Co.

&

Indianapolis.Jndiana 46206

7092,

Printed in U.S. of America

editorial or pic-

NC NC

NC

25J iL 22J

J2

4,

<

F6

2

TL

J2

/.

3

A PHOTOFACT

STANDARD

NOTATION SCHEMATIC

with

BBgni

©

Howard

W.

Sams

& Co.

1987

TANDY

MODEL 1000SX

TROUBLESHOOTING

TEST SETUP

Connect

properly

Connect

B. Use

test

Disk Drive.

WARNING:

Drive

diskette,

tected.

diskette

ed

up on another

alignment

voltages

alignment

cause

tions of the alignment

diskette

Check a I I setup

correct

cables

ing

HEAD

CLEANING

Use

a cotton

with

91? isopopyl

free

Diskette

CONTINUOUS OPERATION

Use

the following

A running

Change

37

to make Drive

10

Disk

a

Drive

to the Computer

the

defective Disk Drive

Disk

program

to

Drive A

needed to check

It is

possible for a defective

write on or

even

Check

that

if the diskette

the Disk Drive

has

programs that

diskette. Do

diskette

in the drive

and waveforms

procedures. The

the Disk Drive

is write

protected.

jumpers

positions

for good

and check

connections.

INSTRUCTIONS

swab or

cloth or

.

alcohol

use a non-abrasive

OF DISK DRIVE

Basic

continuously

the number 20

B run

OUT

1014,128:OUT 1010,20:GOT0 10

OSCILLATOR

Verify

checking

Drive Controller

missing or

Crystal Y1

RAB

from

the

oscillator

the 480KHz

the frequency

Capacitors

,

pin 4

IC (U3).

to pin

WILL NOT READ

Insert

Drive

the

Drive

To

1014,128:0UT

The

itor

a diskette

B

and close

containing

the door. Type

following Basic

running

10

CLS

20

OUT

30

OUT

40 OUT

50

FOR X=1

60

S=lhP(1013):S=INP(1012):PRINT

70

NEXT X:L0CATE

80
90

GOTO

operate

In read mode.

1014,128:0UT

1013,74:S=INP(1012)

1013,Y:S=INP<1012)

7

TO

IF Y=1 THEN Y=5

20

Drive A,

1010,16:OUT 1010,20.

program

screen. The

displays

numbers should

known to be operating

as Disk Drive

to load any alignment

Disk

as

the defective

erase information

is write pro-

by first

have been back-

not

leave the

while

unless

circuits

lint- free

in the program

specified

test

equipment

and

all

to erase

even

switches

I

nterconnect-

diskette

cloth dampened

and dry with a lint-

program

in the read

to keep

to number

continously.

Is working properly

waveform

C13

5, and IC U3.

at

If

not

correct,

and C14,

pin

waveform

data

program

to keep

In and

the

1010,33:OUT 1010,37

1,1

ELSE

Y=1

change

line 10

seven numbers

S

on the

change

Drive

Disk

on a

using

checking

In the

may

sec-

if the

for

cleaning

Drive

mode.

by

37

of

check

Resistor

In Disk

run

Disk

to OUT

Mon-

when

diskette

Drive

above

High

A.

J1 on the. Disk

Drive

or

If reading

Drive

and

program

on

is In read

Interface

Board. If

logic Low

(U3). If reading

If

a

reading

pin 2 of

closing

Drive).

in the

and closed.

head winding

J9

for good

ages and

26

thru

(U5).

IC U4,

pulses

are

present,

the

Disk Drive

Computer

WILL

NOT

Insert

and

close the

lowing

to the Diskette

upper left

number

write

protected

protected

f the

I

"Write

this Troubleshooting

10

20
30 S=INP(1012)

Is

40 OUT 1013,77:S=1NP(1012)

50
60

70
80
90

100

110 PRINT INPC1013)

120

130

140

150 IF Y=1

160

NOTE:

diskette

are

not working.

pin 11 of

running

pulses

sor"

While

pulses

pulses

a

check

are missing,

section of this

the

at pins 22

are missing,

the

with data

the Drive

the Write

Is not

reading

at

is

Buffer IC

the

There

waveform

If

connections,

components

34

and

If

the waveform

check

are

for pulses

missing,

check

on

It

Is running, check

door

gate (pin 24)

Drive

Board

mode.

correct,

circuit

pin 10

correct,

Drive

should

as the Drive

there

for continuity,

on the

is correct, check

of Drive

is not correct,

check

(U4) while

door (with

be a noticeable

is no

and

associated

thru 44

of Read/Write

checks good

at

check IC U4.

the Drive

Interface

System Board.

WRITE

a blank diskette

Basic

should

numbers

Protect

CLS

OUT

door. Type

program

and

corner

Diskette

of the Monitor screen.

be when the Diskette

and

is inserted

are not correct,

Does

guide.

1014,128:0UT

into the Disk

In and

which

displays a

change

Function"

Not

1010,33:0UT 1010,37

OUT 1013,Y:S=INP(1012)

OUT

1013,1:S=INP(1012)

OUT 1013,12:S=INP(1012)

OUT 1013,12:S=INP<1012)

OUT

1013,0:S=INP(1012)

S=INPC1013):S=INP(1012)

FOR X=1

TO 5

AND 2:

S=INP(1013):S=INP(1012)

NEXT

X:L0CATE

THEN Y=5

1,1

ELSE Y=1

GOTO 20

this

program will

If the diskette

Check

Buffer

with

IC <U4)

a

blank diskette Inserted.

index sensor

refer

for Index

while the Drive

to the "Index

Troubleshooting

above program

and 24

Disk

Drive

Is running, check

of Connector J1.

check the Drive

Interface

is inserted

closed.

of Connector

to verify

check the

Computer

for

In the

While

a logic

the Disk

System

for

the

Disk

Controller

check IC U3.

the waveform at

opening and

diskette

change

door Is

change, check

check

opened

the

Connector

check the volt-

with

pins 1

Amp IC

at pin 2

3

pin

of IC U4.

If

cable

circuit

pulses

and check

on the

Drive

writes

run the fol-

continuously

number on the

The

2

to

when a write

into the Drive.

refer

is not

to the

section of

NPdOl 2)

S=l

not write to the

circuits

pulses at

Sen-

guide.

for

cable and

circuits

on the

a

IC

in

o

of

CO

If

o

to

CO

s

o

m

fe

<

©

o
w
X

is

If

If

TROUBLESHOOTING

(Continued)

Computer

check for pulses at

Drive

ing, check IC U3. If pulses are present,

System Board. If

Controller IC U3. If

pins

>u!ses

>

check the head windings for continuity,

Connector

J9

for good connections, and

are present,

(TP2)

pulses

10

and

are miss-

check

check

the voltages and components associated with

12

pins

WRITE PROTECT DOES NOT

Type In and run the program listed

"Will Not

ing guide.

ber

on the left

screen if

ed

If the diskette

is

inserted

WARNING:
diskette.

on it

that

protected diskette

the

door.

While the program

protected

for a

logic High at pin

reading

good

connections and check the Write Protect

Sensor

for a logic

5

of Buffer IC U4. If reading

at pin

reading

pin

5,

27

thru

of Read/Write Amp IC (U5).

FUNCTION

Write" section of this Troubleshoot-

The program

diskette that

a

Into the Drive and the number

is write protected.

This

program also writes

Do

not use a diskette that has data

important.

is

will display the num-

upper

corner

is not write protect-

of the

Insert a blank write

the Drive and

Into

running, insert

is

diskette Into the Drive and

5

Connector J5.

not

is

(PQ52).

correct, check Connector J5 for

High at

check

4,

correct at pin

is

if reading

Drive

of

correct,

Is

pin

4

and logic

Low

Is not

Controller IC (U3). If

4

and not correct at

check IC U4.

under the

Monitor

on the

close

a write

check

check

at pin

correct

40

FOR

50

of

OUT

60

S=INP(1012)

70

OUT

80

OUT 1013,2:S=lhP(1012)

90 CLS:PRINT INPC1013) AND

100

GOTO

DRIVE

B

10 OUT I014,128:0UT 1010,33:OUT 1010,37

20

OUT 1013,7:S=INP(1012)

30 OUT 1 01

40 T=1 TO 500:NEXT
50

OUT 1014,128:OUT 1010,33:OUT 1010,37

60 S=INPC1012)

2

70 OUT 1013,4:S=INP(1012)

80

OUT 1013,2:S=INP(1012)

90 CLS:PRINT INPC1013) AND 16:

100

GOTO

If the number

rect, check for a

head is On Track 00
head is Off Track

check Connector J4

check

If

correct,

tions,

Resistor RA7

are correct, check

and

logic Low

a

with the head On Track

pin 14

head

and

Off Track

rect at pin

(U3). If readings

not correct at

T=1

TO 500: NEXT T

1014,128:OUT 1010,16:OUT 1010,20

1013,4:

S= I NPC101 2)

16: S=l

NPC101

40

NP (

3,

1 : S= I

01 2

1

T

1 01 2)

S=l NP C

40

on the Monitor screen is

High

logic

and a logic Low

00.

the Track 00

from

pin

for a logic

at pin

'

a logic High

00.

If

check

14,

5

to

00

readings are not cor-

at

If readings

for good

Sensor (M2) and

pin

13

of Buffer IC

and a

at ptn

Drive

are correct at pin

1.

High

not

TP3

when the

when the

are not

connec-

If

readings

at

Low at

logic

13

with the

Controller IC

14

pin 13, check IC U4.

pin

2

cor-

14

(U4)

and

INDEX SENSOR

To check the Index Sensor circuits,

and run

Operation

ning.

close

3 of

check Connector J5

tor RA7
sor

pulses at

pulses

IC

pulses

ing, check IC

check pin 8

the program given under

Disk Drive"

of

Insert a diskette

to keep the drive

In the Disk Drive

the door. Check for pulses

Connector J5).

If pulses are missing,

for good connections,

from

(PQ51).

pin

are

(U3>.

2

pin

to pin 1

|f

pulses are present,

12

of

the

Buffer IC (U4).

missing, check the Drive Controller

If

pulses are present, check for

at pin 11 of IC U4.

U4. If pulses are present,

of Connector J1

and the Index Sen-

If pulses are miss-

for good

tions.

TRACK 00

Disk

stop.

program

circuits. The

to

Monitor

Track 00.

Track 00

number

DRIVE

SENSOR

Drive Head

Type

to

bangs

in and run the following Basic

check the Track

program will step the Head

Track 00

and display the number 16

screen to indicate

If

the head Is manually

the number

0.

A

10

OUT

20

30

1014,128:OUT 1010,16:0UT 1010,20

OUT 1013,7:S=INP(1012)

OUT 1013,1:S=INP(1012)

against the Track 00

00

the head is

should change to the

type

"Continuous

run-

TP1

at

(pin

Resis-

check for

connec-

detector

back

on the

pushed off

DRIVE

MOTOR

In

and

Drive Motor

J7

and

tions.

1

pin

Board.

on

will not

Disk Drive Board

the

run.

Check for 5.0V at

of Connector J2 on the Disk Drive

If the voltages

Check

for good connec-

pin4and

are missing,

power supply.

Type in and run the program given under "Con-

tinuous Operation

If

Drive

16

If

running.

of Connector J1 on

reading

cable and

the

Computer System Board.

correct, check for a

Connector J7. If

check the Drive

reading is correct,

good

connections and

not correct,

Is

check the

Disk

of

Drive" to keep the

Check for a logic Low

Disk Drive Board.

the

check the Drive

Disk

Drive Interface on

If reading is

High

logic

reading is not correct,

Controller IC (U3). If

check Connector

check the

Control Board.

STEPPING

Head

on

run the

continuously alternates

between Tracks

MOTOR

position motor

not

following Basic program.

00

and

16.

working.

the head on Drive B

DRIVE A

10

OUT

20
30

40

1014,128:0UT 1010,16:OUT

OUT 1013,7:S=INP(1012)

OUT

1013,1 :S=INPC1012)

OUT T=1 TO 500:NEXT

T

Connectors J1

12.0V

the

check

at pin

J7

3

of

for

Motor

at pin

Drive

Type In and

program

The

1010,20

at

50 OUT

60 OUT 1013,15:S=INP(1012)

70 OUT

80 OUT

90

100 GOTO

DRIVE B

10 OUT

20

30 OUT

40
50
60

70

80

90

100

1010,20

1

01

: S= I NP

3, 1

1013,16: S=l

FOR T=1 TO 500:NEXT

10

1014,128:OUT

OUT

1013,7:S=INP(1012>

1013,1

OUT T=1 TO
OUT 1010,37
OUT

OUT 1013,1 :S=INPC1012)
OUT

FOR

T=1 TO 500:NEXT

GOTO

:S-lhF(1012)

500:

1013,15:S=INP(1012)

1013,16:S=INP(1012)

10

TROUBLESHOOTING

C 1 01 2

) the Disk Drive Interface

NPC1012)

T check

1010,33:OUT 1010,37

NEXT

T

T

(Continued)

While the program

at

are missing, check the Drive cable and

puter System Board. If pulses are present,

Driver

Drive

ent, check for pulses at pins 10

U7.

itors C37 and C38, Connector J6,

Stepping

18

pins

for

pulses

I C (U7). If pulses are missing, check

Controller IC (U3). If

If pulses

Motor (Ml)

and

of Connector J1. If pulses

circuit on the Com-

at pins

are missing, check IC

windings

running,

Is

20

check for pulses

4

for continuity.

7

thru

pulses are pres-

of Motor

13

thru

U7,

and check the

check

of

Capac-

IC

o

o

c/>

CO

o

S-

m
o

o

(/)

X

1

^

<

GridTrace

LOCATION

GUIDE

C2

C4 J

K-1

-3

C5 K-3
06

C9
C10

K-1

G-3

G-6

C13 F-11

C14
C17

C18

C19

F-11

D-2

C-1

D-2

C20 C-2

C21 F-7

C22 E-7

C23

D-7

C24 D-6
C25 D-6
C26 F-8

C28

D-9

C29 B-1

C32

B-4

C37 C-8
C38

B-8

CRA3 E-1

DSO K-6

DS1

J1

J2 L-3

J4

J5 F-1

J6 C-10
J7 A-2

K-6

M-8

J-1

J9 G-1

L3

C-5

L4 B-3

L5 A-4

Q3

R1

F-9

E-3

R5 K-5

R6 K-7

R9

R11

R13

G-4

F-4
E-3

R14 D-2

R15
R16

D-3

C-3

R20 D-10

R21 D-11

R22 A-4
R23

RA1 L-9

RA3

RA4

B-8

-5

J

1-5

RA5 K-9

RA6

1-10

RA7 G-3

RA8
RA9

RA11

TP1 C-4

G-1

E-6

C-2

TP2 C-5
TP3

TP4

TP5

TP6

TP7

TP8

C-5

C-5

C-6

C-6

C-6

C-7

U3 H-8
U4

U5

U7

Y1 F-10

H-11

E-5

E-10

4 5

3

M

: i

•

:

*;;

*-

4,

13

7

6

™.,

:.™ ..-

8

;:,:

9 10

,;

MiM,

II

A

!

C

jjiSt,

*

•

'IMP

MIUKMMimPII

^HffMtt

H

m»*»*.

"^

;

D

M

2

3 4

7

8 9 10

11

A

Howard W.

Sams

EJJ30|^SS

Photo

w

LU

o

z

z

o

t-
OL

cc

O

CO

LU

Q 2

o

en

m

O

•n

c

It!

j-

k

b
3

z

as

Q.

O

o

o

«

« o

JS

(0

to

£

XI

«-*

c

a>

E
o
a

Q.

o

a>
a>

1

t

<

n

o

c/>

o

C/>

CO

6

°

fc

a,

o

d

Z

C3

(A

3

0)

(A

0)

<

a.

d

DC

Z

<
a

No.

No./

MFGR.

TYPE

PART

SS233F

DTA144EF

LH5060B

1

M2167

CN

o

CN
CD

O

LU

NTE2072

M54534P

BA6581K

NB2803P

m>

o°

o

o

w
X

<

No.

to

0)

t-

<

a.

d.

a

CD

^

-£

7Z

o

&

o

I

I LU

§ (0

ITEM

DRIVE

DISK

CRA3

Q3

.

U3 U4

U5 U7

PARTS

When

ordering parts,

LIST AND

state Model, Part

DESCRIPTION (Continued)

Number, and

Description

ELECTROLYTIC

ITEM

No.

C37
C38

RATING

DISK

6.8

6.8

CAPACITORS

ITEM

No.

C21

C29
C32

COILS (RF-IF)

ITEM

No.

L3

L4

L5

RATING

DRIVE

DISK

lOOpF

.0022 500V

.0015

FUNCTION

DISK DRIVE

Peaking

Peak

ng

I

Peaking

CAPACITORS

DRIVE

25V

NP

25V NP

500V

2%

2%

500V

2%

MFGR.

PART

PART No.

No.

MFGR.

MFGR.

PART No.

ITEM

No.

ITEM

ITEM

No.

No.

RATING

FUNCTION

RATING

MFGR.

PART

PART No.

No.

MFGR.

MFGR.

PART No.

CONTROLS

ITEM

NO.

DISK DRIVE

R1

RESISTORS

R9

R22

RA1

RA3

RA4

RA5
RA6

RA7

RA8

RA9

RA11

(1)

<2)

(3)

(4)

ITEM

No.

1000

10K x

56K,

10K

Balance

5h9

2,

10K,

x

4,

wattages

(All

FUNCTION

watt, or less, unless listed)

1/2

RESISTANCE

20K

(Power and Special)

RATING

DISK DRIVE

2670

200

Resistor Network

Resistor

Res I stor Network

Resistor Network

Resistor Network

Resistor

Resistor Network

Resistor Network

Resistor Network

56K

1000, 2200

56K

1/8W Carbon Film

\%

1/8W

\%

Carbon

Network

Network

2

x

x 4

and

Film

4700

x 2

MFGR.

PART NO.

MFGR.

PART No.

(1)

(2)

(3)

(4)

(4)

(5)

(6)

(7)

(8)

(5)

18K x 4

(6) 56K x

(7)

22K, 39K, 15K,

150

(8)

x

REPLACEMENT DATA

NTE

PART

1

1M

x

2,

2,

2000 x

150

2,

390

NOTES

No.

WORKMAN

No.

PART

PARTS LIST

AND

When ordering parts, state

MISCELLANEOUS

ITEM

No.

LED51

M1

M2

M3
M4

PQ51

PQ52

DISK

LED

Motor

Sensor

Motor

Head

Sensor

Sensor

PART

DRIVE

NAME

DESCRIPTION

Number,

Part

Model,

MFGR.

PART

(Continued)

Description

and

No.

Activity,

Stepping

Track 00

Drive

Read/Write/Erase

Index

Write

NOTES

Red

Protect

<? Isolated

*—

Circuitry

—

Circuitry

e

See parts

+

Ground

"+"

Chassis

Voltages,

drive

disk

running

shown

not

NOTE:

were

moving

protected)

gram.

Probe

(1)

(2)

Probe

when head

H

Probe

(3)

L when

Probe

(4)

and L

(5)

Probe

and

Probe

(6)

and

center of

Probe

(7)

and

center of

(8)

Probe

Probe

(9)

(10)

Probe

Probe

(11)

(12)

Probe

protected.

Probe

(13)

protected.

(14)

Voltage

ground.

not

used in

list

waveforms

interface

following

the

taken

unless

Insert a

in

indicates

Indicates

Indicates

head

indicates

when

indicates

H when

indicates

L when

Indicates

H when

indicates
indicates
indicates

Indicates

indicates

indicates

varies

used in

when the

noted.

formatted

Drive

1 is

1 is

off

off

head is

the

head is

the

some

versions

some

logic

and

disk

and

Basic

B before

P when head

L when

selected.

when head

H

selected.

H when

track 00.

when,

L

00.

track

H when

diskette.

when

L

diskette.

when

H

when

L

H when

when

L

L if

H if

head is

when

SCHEMATIC

versions

readings for

drive

program.

drive

disk

diskette

running

is moving.

head is

head Is

head Is on

is

head

moving

moving

head

head

Drive Motor

Drive

out

head is

out

is moving,

is moving.

Motor

diskette

diskette is

moving.

while

taken

Readings

head

(not write

the

selected,

selected,

is

track 00

on

track

moving in

from the

moving

from

off.

s

is off.

is

NOTES

Terminal

on

Capacitors

less

the

was

pro-

00 Voltages

in

the

write

write

Electrolytic

less,

Resistors

noted.

Value

Measurements

less

Logic Probe

L

H
P

*

Waveforms

ground,

Supply

i nput.

Controls

unit.

noted.

20? unless

In

noted.

=

Low

=

High

=

Pulse

=

Open

Identification

50

are

capacitors

noted.

are I/2W

() used

In some

with switching

Display

(No lights

measured

unless

voltage

with

and

noted

maintained

adjusted

may

volts or

are

or less, 5%

versions.

On)

...

digital

voltages

otherwise.

normal

for

be found

not

less,

5%

volts or

50

unless

shown, un-

as

meter

taken

shown

as

operation.

un-

from

at

3

O

m>

o

o

c/>

X

<

10 OPEN

20 FOR X=1

"B:

30 PRINT #1,

SAMS. DAT"

300

TO

"HOWARD

FOR OUTPUT AS

W SAMS"

40 NEXT X

CLOSE #1

50
60 GOTO

10

EQUIPMENT REQUIRED

A lest program

required
select

track specified

Use

when

alignment

diskette has

does

which will

side or 1 and step

a Dysan Analog Alignment Diskette 224/2A

an Alignment Diskette

procedures.

only

not contain any alignment programs.

a Disk Drive Tester

or

turn On

In the

NOTE: This

alignment

the

the

alignment procedures.

Is specified In

patterns on It and

Disk Drive,

head to the

DRIVE TRACK PROGRAM

ALIGNMENT

The speed

stand stll

Is

the

alignment

Is correct If the pattern appears to

I.

A*Y°fv

STROBE

PATTERN

The following Basic

step

specified by

press the Ctrl

NOTE:

the Disk Drive

the

and Break keys.

The

programs select side

programs can

user. To

head to the

stop the program,

be

only.

used

Track

Operates Drive A

10

CLS

20

OUT

30

1014,128:OUT 1010,16:OUT

OUT 1013,7:S=INPC1012)

40 OUT

50 INPUT

60
70

80

90 OUT 1013,1:S=INP(1012)

100

110 FOR T=1 TO 400:NEXT

120 PRINT"PRESS

130

1013,1:

"ENTER TRACK NUMBER

IF TR>40

OUT 1010,20

OUT 1013,15:S=INP(1012)

OUT

1013,TR:S=INP(1012)

A$=INKEY$:0UT

NPC101 2)

S=l

THEN 50

ANY KEY TO STOP"

1010,20:IF A$="" THEN

T

";

1010,20

TR

130

ELSE 50

Operates Drive B

10

CLS

20 OUT

1014,128:0UT

1010,33:OUT

1010,37

30 OUT 1013,7:S=INP{1012)

40 OUT
50

60

70

80 OUT

90

100

110
120 PRINT"PRESS ANY KEY
130

ELSE

1013,1:S=INP(1012)

INPUT "ENTER

IF TR>40 THEN

TRACK

50

NUMBER

OUT 1010,37

1013,15:S=INPC1012)

OUT 1013,1:S=INPO012)

OUT 1013,TR:S=INP(1012)

FOR T-1 TO 400:NEXT

A$=INKEY$:0UT

1010,37: IF

50

';TR

T

TO STOP"

A$="" THEN

130

SPINDLE SPEED CHECK

If

Disk Drive

a

Tester which provides

readout of the speed In rpm ts being used,

check for a speed of

If

Disk Drive

a

center and paste a strobe pattern

motor

Figure

and close

program

Disk Drive"

Use the outside pattern

flourescent

pattern

on the bottom of

1. Insert a

the

1 1 sled under "Continuous Operation of

to

lighting Is used or the Inside

for 50

300

rpm

Tester

diskette

door. Type

keep the Disk

cycle

lights.

+4.5rpm.

ts not available,

Disk Drive,

the

In and run the

the Drive

on

Into the Drive

Drive running.

when

60

see

cycle

to

'/mi*

Figure

1

RADIAL HEAD ALIGNMENT

Connect the channel A Input of

scope to

external trigger

lead to

channel Inverted, the sweep time to 20mSec

one
and

the voltage range to

Inputs 1o AC. Insert the Alignment Diskette

Into the Disk

On the Disk Drive and

16, Side 0. The cats-eye pattern shown

TP7,

channel

Input to

TP6. Set the scope to add mode with

Drive and close the

B

TP1.

.2V.

step

a dual

TP8,

to

Connect ground

Set both

the head

Figure2should be displayed on the scope.

EQUAL AMPLITUDE

Figure 2

The

amplitude of the two lobes displayed must

within 70$ of each other. If the lobes

be

out of tolerance,

Stepping Motor

loosen two

(M1).

Adjust

screws

Motor

two lobes are equal In amplitude and

Motor

stepping the bead

Track

16,

a

on Track

mount screws. Check the adjustment by

then to Track 00

16,

to

Track

39 and

back to Track

and

checking the lobes each time the head Is

16. Check the Track 00 Stop and

Detector adjustments after performing

Radial Head Alignment. Select side

check

Radial alignment of

Head 1

above procedures.

TRACK 00 SENSOR

Connect a

to 20uSec.

Insert the

Drive

Drive and

scope to TP8

Set the voltage range to

Alignment Diskette Into the Disk

close the door. Turn On

and

the Head to

set

stne wave should be

and

displayed on the scope.

the sweep time

set

Track 00. A

trace

the

and

scope

door. Turn

to

track

are

holding

until the

tighten

back to

the

1

and

using

the

.2V.

the Disk

125KHz

In

10

If the 125kHz signal Is not present, step the

ALIGNMENT

head forward

present. When the

Is

on the scope, the head

Connect the Input of

Check

0V

readings

Track

for 5V when the Head

when the Head

are not correct,

01,

screw(see Disk

of the Disk Drive

top

until

5V. Tighten

the voltmeter

the Track 00

INDEX

SENSOR

Connect the channel A

scope

pulse)and

scope display

range set

50uS. Set

mode

the

trigger set to negative

TP8,

to

the scope ground to

to

and trigger the scope on channel B wtth

or

back

until

125kHz

Is on

Is on

the 125kHz

signal

Is present

Track 00.

a voltmeter to

Is on Track

Track 02.

set the

loosen the Track 00

Sensor (M2)

Drive Mechanical Photo)on

and adjust

the

reading jumps fr^m 0V

the Track

00

screw and recheck

Sensor adjustment.

ADJUSTMENT

of a

channel B

to channel A with the voltage

20mV

the channel B Input

Input

Input to

and the sweep time set -ho

dual trace

TP6.

nonlnvertlng

to

slope.

signal

00

If the

Head

detector

TP1

( Index

Set the

TP3.

and

the

(Continued)

AZIMUTH CHECK

Connect the channel

scope

trigger

ground to

channel B

put, trigger to

to

.1V

Insert the Alignment Dtskette,

Disk

to

track

shown

and 4 must be

amplitudes

If

side

the azimuth of Head

TP7,

to

channel B Input

Input to TP1

TP6.

Set the

Inverted,

negative

range.

Drtve, select

34.

Confirm that

Figure

In

side and set the head

4. The

equal

of bursts

the azimuth of Head checks

1 and repeat the

1.

A

Input of

and connect

scope to add mode

sweep time

a dual trace

TP8,

to

to .5ms,

external

the scope

slope and voltage

turn

on

the pattern appears as

amplitude of bursts

to or less than the

2

and 3.

good, select

above procedure to check

AC

with

In-

to

the

to

1

Insert the Alignment Dtskette

Drive and

select side

close

the

door.

set the head to track

and

Turn On Disk Drive,

In the

Disk

01.

Confirm that the leading edge of the burst

occurs

the Index pulse, see

Sensor

200uS

(PQ51)

screws holding

±200us after

Is out of adjustment, loosen two

the board

detector on the top

adjust the Board for

Drive

Mechanical, Top

checks good, select side

above

procedure to check

the leading edge of

Figure 3. If the Index

with the Index

the Disk Drive and

of

200ust200us,see Disk

View Photo. If side

Head

1

and repeat

1.

the

Figure 3

Figure

READ

CIRCUIT ADJUSTMENT

To

do this adjustment a Disk Drive Tester or

4

program Is required that will continuously

write

a 1F

<62.5KHz)

pattern on a blank

dtskette Inserted In the Drtve.

to

phase,

IC U4

door.

the

the

will

see

one

of

Connect

(Read Data Line). Set the

Sec,

the Input

voltage range

negative slope. Insert a

the Drive

and close

Continuously write

scope to pin 3 of

a

to

sweep time to 2u

2V

and

BLANK dtskette In

Drive

the

IF

a

pattern

trigger on

diskette. Two pulses should appear on

scope screen. If the

Is out of

appear

Figure

It until the second pulse appears to be

pulse, see Figure

to be

5.

adjustment,

two

If R1

6.

Phase

the second pulse

pulses

out of adjustment, adjust

Is

out of

2 pulses

Control (R1)

AdJ

2

o

S-

o

o

w
X

1

<

Figure 6

11

c

•

:

''

:

•(."

12.0V(

NOTE:

12

)

ARROWS

ON

5.0V(C)

IC'S

U5

U3

U7 03

INDICATE PIN 1 UNLESS NOTED

Howard W.

A

Sams MhMHH.W^ Photo

U4

LE061

5.0V(C)

o
m

z

§

^
<

OTHER

LOCATED

ON

Howord W. Scms

A

SIDE

THE

OF

MTWUirEreS

BOARD

Photo

13

I

IMI

TRACK

SCfiEW^

12-"

PQ51

INDEX

SENSOR

SCREWS

00

m

mm

iH

It

11

<B

CHASSIS-TOP

14

¥IEW

MNINi

LOGIC

CHART

FLOPPY

PIN IC

NO. U3 NO. U3

1 LC13) 21 P 41

2
3 L 23 L(13) 43 L(l)

4

5 H 25

6

7 H 27 L 47

8 H 28 L 48

9

10 P 30

11 L(8) 31 H 11 P 31

12

13 H 33 L 13

14

15 L(10) 35 H 15

16 L

17

18 H(1)
19 P 39

20

DRIVE

DISK

PIN IC

H

*

L

P 29

HC1)

H

H(7)

L

22

24

26

32

34 L 14

36

37 P

38 H

40

PIN IC PIN IC IC PIN

NO. U3 NO. U4 U5 NO. U5

LCD

L(4)

H

H

L 46

L 9

L

L 12 P 32

P 16

P

42

H(1) 2

44

H(1)

45

H

*(9)

H

L(4) 8 L 28

1

3

4

5

6

7

10

L 21

P

P 23

L(13) 24

H(12)

H 26

L 27 H

L 29

H 30 P

H(5) 33

L(4)

L

H

HC11)

IC

22

25

P

P

H(2)

H

P

TERMINAL

2

h2h<?hs

nnnnnnnnnnn

i=

34

C

35

C

36

SVC La 19

1=

38

C

39

t=

40

C =115 44 C

41

C

42

1=

43

o

P

44

UULJULIUULiUULl

1

3

2

4

TOP

567

U5

n

VIEW

2g'

8

5

910

2<P

11

lom 3

,

p22

=3

21

b20

=118 41

17 42

P

=1

16 43

bl4

pi3 46

p12

GUIDES

5

W%i

%s

nnnnnnnnnnnn

t=

37
38

q

1=

39

40

P
q

C
C

451=

C

4?C=

o

a

48

^uuuuuuuuuuuu

1

3

2

3

WW%s

S

4

678

TOP VIEW

m

8 C E

93

FRONT VIEW

910

IDENT

/

12

11

15

TP8

::;:.:

f

.

.jmmmmm^

-v.: .-.-

;:

-...

,;

;:.

.:

;. ..

,

::

ii/

:

f#i.;;i

jj/

7

.TP7

,^TP3

JS|/

RADIAL

ALIGNMENT

SCREWS

/ 1 /

I

Ai,

I

°

•

1

''

§

1

mm 1

'

•

ft*

PHASE

ADJUST

^-~R1

-

—

TP1

CHASSIS

BOTTOM

VIEW

16

c

„

O UJ

& y

e

<

o

^

U

t

*

P

"5

2

i If JU

"

llm

in

it

in

o

o

-

o

ns

D.

"

"»

•n Z

-

u c

n;

L^

ctf

a3

J=

.&

M

-

l:

"2

*

o

5

E

°

e

o

3

c

c

^

*

o

-

3

CJ

CJ

o

E

g

<-i

u o

>,

w

-"=

jT

'_>

^

C/5

-j

r.

to

J3

D.

t:

«

£

2

S

g

e

a

E

c c

O

4J

E

* -

o

c

S

U

I

"&

w

°

«»

C c

aj

r \ e

cj

'—

—

O

9,

'5

s

£ D

°

7

UJ £

<

1-

<

—

z

-J-

UJ

<

a.

UJ

(9

z

—

£

z

z

-

i-l

?

£

r*l

OrnM

r*i

o o—o

6

z

<

=

^

re

r- r-
r- r-

-

* IN

-

5

?.

S 5

^

a* &

j;

w w yi w

z

JJ

-

;>

J*

*

?*

UJ ill LJ Lii

z z z z

z

£:

S

£ 2

V O

w

C!

u u u u

'Jj UJ Lit UJ

2 £

d r- «

4

r- *n a r-

*m in *? r<i
&. B*

—

3-

"T

f

- ~

—

— fl

-.

Ul

—

z

ft,

ir»

£

fi

**i

3 z z

£

If

1^4

r-i

_ ^* r-.

O O Q O Q

C 2 3 D S

o

J

E

J-

6*

£

o

§1

lb

—

^

c

.2

M

a

»yl

wo:

t

O

(Tl

.£

<"

r

00'

SSr

S

|-3«

5

ft-

.E

so?

s

a

-

c

>.

--J

'J

c

.2

bJ

£
—

o

H

i-

<

- '

o

*

u

°

O

oo

t-T

w

aj

C

—

O

o

a

H5i

¥

.2 5

=

O

a:

2

§

c-n

Q

O

as

on

a

CJj

1)

J5

Ml

c

n

q

E

o

~*

on

3

O

3

u

ss

w

*

.£

ii

=

s

3

.5

c

e

c

0£

.s

c

3

C

!_

"os

i-

>

en

U

e

*j

X!

ri

3

>

>>

c

<a

E

J=
'—

c

o

nS

z

3

D,

-
<

_

UJ

H

-
c

—

'3

M

C.

o

M5

>.

a,

-

>v

'J

c
e

'5b

u

i5

c

u

>

c

'53

3

•j

BJ

E

o>

4S

u

r.

C

o

o

3

—

S3

u

:

—

E

—

-

3

r5

(A
<U

DO

n

o

>

^>

01)

05

>

'J

u

a

a

—

—

3

.5

i-

E

•—

q

u

E

o

E

s

t/1

5

-

1/3

e

—

cd

>

cd

a

2.

=

o

a

>

"a

_3

CJ

X
u

IE

g

—

c

3

o

V3

a

*

-

r-

<

"C

0)

IS

'S3

a
c

PS

tn

C

2

s

E
o

~~

a

o

C/J

_^

x:

U

u

"5

C
c

.2
'G

'S

—

i

u

CJ

ca

.-.

^

:

3

—

<

-

:-

Dm

o

u

"3

Q,

v:

a

S

«

»—

c
c

c

a.

E
c

u

C

'S

u

J3

H

'5

E

CJ

EU

3

B

E

X

•

u

u

•J

3
U

'j

c

X

--1

3
G

E

an

<

•

-

_

<

H

iu

U

u

<L>

c
u

3

C

3

Ed

3

.a

O 3

u

O

u

z

CJ

ci)

-

c

CD

H

=

-3

u

J
i

X3

—

eu

CJ

CB

—

c

s

3

Si,

J=

2C

-

3

u

\H1

c

,

£*

5 rt

=

«

>.

ta

o

O

"

v

=

=

ai-;j;

.

—

<" °

_

-^

„

I—

r-

g

g

=

6B"S|

.

o

O

n

C

jH

u

„

O d

—

1/

St

S

'

^ SB-C

=

s

—

3

eg

3

CJ

—

CJ

c

ao

c

3

-

CJ

—

It

s.

a

be

3

'E

CQ

E

~

3

U

§

a

c>-

J

cj

U

ii3

3

5

nJ

s

— 3. I

_a-I

-D.I

a=

_C3

8

Jfl.1

3

_a.T

d

MS

JLI

a

k5

-S.3

a.z

—

rNr^

S

—

s

^ ^ ^

Zq

n.z

—

rJ

<-l

8

!^3

a. 0.0.

a-Z