Sharp MZ-80SFD Service Manual

SHARP

SERVICE

MANUAL

PDSMX81014-MZ

Single Floppy Disk

MZ-80SFD

FEATURES

• High

•

• Simultaneous reading and execution

•

• Expanding up

speed

reading and

Easy

deletion and additionofprograms.

Linking

programsby"CHAIN,

to

writingofdata and programs.

four

drivesbyone

SWAP"

SHARP

of

programby"RUN" command.

I/O

card.

command.

CORPORATION

------------Contents--------~'\

Specifications 1

of

Constitution Operational principle

Inspection and replacement Trouble shooting guide Power supply Circuit diagram and printed wiring board 15

Packing method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Disassembled views ' . . . . . . . . . . . . . . . . ...21

Replacement parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

single floppy 1

of

floppy disk " 2

of

section.

disk drive main parts . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

11

13

20

23

6

II

r$PE.qlf1t"iiO~$

I ·General specification.

(a

humidity

out

prior such partially

Specification

maximumoffour

(freeofmoisture condensation)

notice

cases,

items mentioned above may be

different

drives)

for

product improvement. In

from

the product.

to

change

--_.

--

---

with-

---_._-

------

--

Item

--

-----

AC

220V

AC

240V ±

DC 12V DC5V

-

± 10%, 50Hz

10%.

50Hz

Daisy-chain system

5.25-inch both-sides flexible disk Double

Soft 280K

140K AC

AC 30W

5 20

Approx. 4

or

single density

sectored

bytes/driveat16 sectors/track (double density) bytes/drive at 16 sectors/track (single density)

220V

± 10%, 50Hz

240V

± 10%, 50Hz

to

25°C in temperature

to

80% in

165 (W) x 102 (H) x 323 (D) mm

kg

* Specifications and design subject

1

>------

-----------------------

1----

• Power supply section specifications

Drive-to-drive connection Recording medium Recording Numberoftracks 70 tracks Sector Formatted capacity

Power supply

Power Consumption

----

~._-----~---_._--

Operating conditions

External dimensions Weight

Item Specification

Input

Output

{CONSTITUTION

• Constitution and Block Diagram

MZ-80SFDisconstitutedbyfloppy unit.

Its

floppy

disk driveisthe

sameasthe drives

Floppy

disk

OF

disk drive

drive

SINGLE

unit,

control

used

for

MZ-80FD/MZ-SOFDK/MZ-80FB/MZ.SOFBK.

[

r--

-

Block diagram

FLOPPY

PWB

unit,

terminal resistor

Power supply

Terminal resistor

Control

circuit

PWB

unit

and power supply

-1-

_O_P_E_R_AT_I_O_NA_L_PR_I_N_CI_P_LE_O_F_F_LO_P_P_···.·y_·.····O..:....-.'

The

floppy diskisdesignedtorotate "diskette," and write in dataathigh speeds

a magnetic disk storage unit,toread

the

by

bringing the

so-called

out

in

direct

magnetic head sector of 70 tracks formed in diskette.

contact

...........

$Kw...···

••.

>............... J

witb a specifil!d track

both

surfacesofthe

1. Fundamental block diagram

Read

Write Write gate

Write

protect

data

Head select

data

Read circuit

Drive select

Write circuit

Write la,*/'

Operation .

d'

In

Icator

/'

0'

-~~

protectr"··"

)-1

(}--:":":'..,..-----""'1'---------.

Write

./

protect

senso!",

,/

,-!lr

IndeX~-'l'--

sen_s~:JJJ'

~

Head load-

.

.,

actuator

I

--'

__

Direction •

Track

...

..,;D~r;;;;iv;.;.e;..s::.,;el;.;.e-ct--f

Head select

Motor

2. Mechanism explanation

This device consists mainly mechanisms.

1)

Read/write head The head spring. diskette easily.

Signals read through FPC (Flexible Printed Cable)tothe amp. circuit.

2) Carriage assembly 2 units of read/write head are carriage. The carriageislocated with motor

3)

Head locating mechanism This mechanism using stepping ball/V -groove system. The type.

One pulse of by

15

L..-

track.

is

The

and lead screw.

is

a high-precision, reliable head locating

stepping

0

, thus pushing forward

1.-..--..----,...-'

Head select Head load • •

s_t_e;..p

__

--.1,.......L--L--L..,I-

Index

00

ON

attachedtothe

head can follow

out

motorisof

step

Control

of

the

signal causes a 2-step

circuit

of

arm

head are

mounted

motor

and screw-driven

7.5°/pulse, steel

the

through

the

transmitted

the

head

Index

I~

Motor

1-

__

following

a leaf

motion

read

on

stepping

plate

rotation by

one

ON

-,

of

the

,I

. .

~.

Rea1/write~"""

~d

Diskette

Motor control

circuit

41

Diskette driving mechanism A small-sized employed. The through

hub, thereby causing spindle pulley check

5) Head load mechanism This

into

the

._~

•

..".

~:I:

\t==:INIJ.-1IlrJ

'.

DC

motor

the

drive belt, spindle pulley and spindle

is

provided with a stroboscope

rotation interval.

is

a mechanism in which

contact

head load actuator.

with

.

the

with tacho-generator

rotation

rotationofthe

diskette. Itisoperated

is

transmitted

diskette. This

the

headisbrought

~

__

~

to

by

is

_

-2-

6)

Write protect detection section A luminous diode and a photo-transistor are used to detect write jacket. (Writing

protect

is

notchofthe diskette and

not

possible when

the

notch

covered with labeL)

Center

hole

Label area

Write protect

notch

3. Interface

1) Interface signal

All

lines areofTTL (transistor-transistor logic).

is

(1) Input signals

of

For input signals there are 10 kinds

input lines,

allofwhich are validatlow levels. These signal

lines are terminated resistor fittedinthe signal voltage levels are

High

level

Low level

Invalid 2.4to5.25V

I

Valid o

I

Input impedance

a 150-ohm

IC

socketofdrive1.The

as

follows.

to

OAV

Pull-up

to5Vat

int~rated

150-ohm

at

resistor

Head

window

Description

7)

Index detection section

This section consists

phototransistor. An index hole

Index

hole

of

diskette parts

of

a luminous diode and a

of

the

diskette

detected by this sectiontodetermine the starting

point

of

a track.

8) Track00 detection section

is

A carriage position

the

When track

9)

Control electronics section

carriage has reached the track00point,

00

signalisemitted.

The electric circuit composed of 2 sheetsofPWB.

DC

the control

motor

other functions with respect load, and

other

detected with a limit switch.

to

control each mechanism

Oneisto

control circuit. The

otheristo

circuits, say, detection and other

to

read/write, step, head

signals.

10) Diskette protect mechanism the

Shutting pletely set in, can give damage

shortening its life-time. back, this mechanism has been adopted so front door

front door, with the diskette incom-

to

the

diskette, thus

To

prevent such a draw-

that

connot

be closed if

the

diskette

improperly in.

control

the

CD

Drive select signals (0

MZ-80SFDisconnectable up

is

These signals are used the

four drive units.

At low levels of drive select signal,

to

3)

to

4 units.

to

select a desired one of

RIW

head

is

loadedtocause the operation indicatortolight up.

Note) The drive requires

to

switch

is

thru 4).

@ Motor

meet the position of use (Drive No. 1

ON

signal The drive motor starts when comes low. This signal

2 seconds after completion

to

be set with a drive select

the

signal level be-

level

becomes high about

of

all operations,

if

no operationiscommanded next. It thus inter-

the

rupts

motor, extending the service life

of

motor.

@ Direction select signal

The signal direction

is

input.

High

Low

@Step

signal This signal direction designated by the direction select signal. The operation from low levels

is

given

to

of

RIWhead, when the

level- - .

Out

direction (to diskette

designate

the

step

portion)

level

- - -INdirection (to diskette center)

is

giventomove the

is

doneinthe

to

high levels.

RNoJ

courseofchanging

shifting

pulse

outer

headinthe

is

-3-

®Write data signal

is

This signal

Each time changing high levels

current flowing in writeindata This write-in performance gate signal

@Write gate signal

This signal being

on

the

sequential

(j) Side 1 select signal

This signal

double-face headofside 0 and high levels and low levels, respectively.

usedtowriteindataonthe

the

RIW

bit.

is

isatlow levels.

at

low levels,

diskette.

operation

is

diskettetoreadorwrite. The

At

high levels, read-out

may be made.

given

to

decide which sideofa

thatofside 1 are selected

diskette.

to

low levels,

headisreversed

available when write

data

can be written

the

RIW

to

or

at

(2)

Output

There are

CD

Index signal

By can disketteisdetected fed from

Usually, this signal level becomes low each time

the hole

leading edge

of

@Track00signal

The low-level state the

outermost trackJ.

In high levels. When at signal however, By adding still motor phaseisreturnedtocause track00signal to

signals

the

following four kindsofoutput

this signal the. starting positionofeach track

be detected. Each time

with

the

drive unit.

is

detectedathigh levels. Therefore, the

of

the

signal indicates

a track.

of

RIW

headislocatedattrack00position (the

any position

the RIW headisat

the position by

to

become low.

other

than

the

step

outside

the

track00signal level becomes high.

another

signaltostep outside,

the

index hole

the

detector,

this signal signifies

track

00,

stopper evenifanother

is

given. At this time,

the

beginning

DO,

the

signalisat

the headisheld

signal.

track

that

the

of

@ Write protect signal

is

This signal protect for the diskette diskette with write becomes low.

In

is

usual operation, a diskette with write protect enables to protect write statement within drive.

.~

Read data signal

The signal diskette. Usually it

detection it comes

usedtodetect

protectisin,

is

giventotransfer

isathigh levels, while during

downtolow levels.

whetherornot

is

provided. When a

the

signal level

data

read from the

write

the

-4-

3) Timing

~\

DC

POWER

MOTOR

ON

DRIVE SELECT

VALID AND WRT

OUTPUT

SIDE ONE

WRITE

TR

VALID

INDEX

DIRECTIO

SELECT

STEP

SELECT

WRITE GATE

DATA

-

KOO

PRT

N

-

--

....

1s

I-

-100ms

I--Soons

I

MAX--j

1J,Ls

MI~

1J,LS

-MIN

-

\

~

....

t:::j

MIN

MAX

~soons

~

4

1--1J,LS

-

MAX

--

MIN

'---

~~

20ms

MIN

10ms

MIN

--

-

..

SOms

MIN

1sec

MIN

~1tlsMIN

1:=35m.

100J,LS

-aJ,Ls

--

'd

~~

((

II

1/

II

u

II

{{

I}

MIN

({

II

MAX

"

II

1000J,Ls

1000tlsMIN

I

MIN-

-

1

[

-

100J,Ls

-~

if-

--1

VALID

READ DATA

2) Power supply unit interface

Specified supply voltageofDCSV/DC 12Visfed from the power supply control

PWB.

50ms

1sec

MIN

~

\

~

VALID

Control and data timing

-S-

MIN

3Sms

MIN~

100J,Ls

!--1000tlSMIN

VALID

I

unittothe J2 connectorofdrive

1

MIN-I--

I

VALID

1. Belt

1) Inspeetion to

see if

the

Check Also make sure

beltisstained with

that

scratch and thinned part.

2)

Replacement

1)

Take

the

belt

off

the

pulley graduallybyhand.

2) For applying the belt, motor rotating

pulley and

the

thenonthe spindle pulley while

spindle pulley.

Note)

1.Inputtingonand be

not

caughtbythe

2. Note

that

off

motor

thereisno

sidesofa new belt.

~

dustordirt.

there·isno

unevenness,

spindle pulley while rotating

put

the

belt, be careful so

belt first on

the

that

pulley flange.

difference between

Motor

pullev

Keep

belt

off

the flange.

both

2.

PWB

unit

1)

Replacement

1) Take connectors

2) Remove 3

3) Detach

PWB

4) For reassembly, take

Note)

In

replacing

which short pins

J3

andJ4off

PWB

unit fixing screws (3 mm).

unit.

the

reverse order.

PWB

unit, itisnecessarytocheck

to

cut

and

PWB.

whether

or

not

terminal resistorisrequired, depending on which

to

drive unit

Short

•

it

use (DRIVE No.).

pin: Detach

PWB

unit·

the

short pins from

and apply

them

to

the

a new

old

PWB.

• Terminal resistor:

If

the

old

PWB

unit

has no

terminal resistor, remove terminal

PWB.

fixing

3 pes.

,...--'0-----=--1

unit

J2

connector

(power)

J3

connector

J1

signa'

connector

J4

connector

resistor from a new

PWB

unit

screw(3mm):

PWB

Socket

-6-

Sharp MZ-80SFD Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual