Oceanic FSD-2 User Manual

FSD-2

5^r"

FLOPPY

DISK

DRIVE

FOR

COMMODORE

C64

TABLE

OF

CONTENTS

Page

1.

Introduction

2

2.

Specifications

3

3.

Installation

5

Cable

Connections

5

TurningOnPower

5

Disk

Insertion

5

4.

Using

Programs

6

Using

Prepackaged

Software

6

The Disk

Directory

7

Pattern

Matching

and

Wild

Cards

8

5.

Disk

Commands

••••»

10

Reading

the

Error

Channel

,

13

6.

Sequential

Files

14

7.

Random

Files

16

8.

Relative

Files

20

Using

Relative

Files

21

9.

Programming

the

Disk

Controller

•

25

10.

Changing

the

Device

Number

••....

28

Software

Method

28

Hardware

Method

29

Appendices

A.

DescriptionofError

Messages

30

1.

Introduction

The

FSD-2

Disk

Drive

isaversatile

and

efficient

disk

drive

built

for

the

Commodore

seriesofpersonal

computers.

This

drive

is

fully

compatible

with

the

Commodore64computer

and

directly

replaces

the

Commodore

1541

Disk

Drive,

giving

much

better

performanceinterms

of

data

loading

and

writing

speed

and

memory

buffer

size*

If

you

are

a

beginner,

the

first

few

chapters

will

help

you

install

and

operate

the

disk

drive.

As

your

skill

and

experience

improves,

you

will

find

more

uses

for

your

disk drive

and

the

more advanced

chapters

will

be

very

helpful.

If

you're

an

experienced

professional,

this

manual

can

give

you

the

information

you

need

to

take

advantageofall

tne

FSD-2

power

and

features.

Regardless

of

the

level

of

your

programming

expertise,

the

FSD-2

will

greatly

increase

the

efficiency

and

capabilityofyour

computer

system.

Pleasebeaware

that

this

manual

is a

reference

guide

to

the

operation

of

the FSD-2

While

it

contains

step

by

step

instructions

and

a

section

to

let

you

easily

use

prepackaged

software,

you

should

become

familiar

with

BASIC

and

the

computer

commands

that

help

you

operate

your

computer

and

its

peripherals.

Remember,

you

don't

need

to

learn

everythinginthis

manual

at

once.

The

first

three

or four

chapters

will

let

you

use

the

disk

drive

for

most

applications,

and

the

following

chapters

tell

you

how

to

set

up

files,

access

any

data,

and

program

the

disk

drive

itselfatthe

machine

language

level.

NOTES:

In

FORMAT

examples,

lower

case

words

need

to

be

replaced

by

an

appropriate

word

or

number

that

you

choose•

2.

SPECIFICATIONS

FSD-2

FLOPPY

DISK

DRIVE

♦Slim

line

construction

(low

profile)

and

fully

Commodore

compatible.

♦Disk

size:

5-1/4

inch

diameter.

♦Capacity

Per

Disk

174.8

kbytes

Directory

Entries

144/disk

Sector

Arack

17-21

Bytes/Sector

256

Tracks

•

35

♦Average

NTBF

rateof8000

hours.

♦Power

Requirements

Voltage

117

VAC,

220/230

240

VAC

optional

Frequency

50/60

Hertz

Power

Dissipation

24

Watts

♦Mechanical

Dimensions

Height,

width,

depth

47.5

X150X268mm.

Weight

2.8

kgs.

FSD-2

FLOPPY

DISK

DRIVER

Figure4.1

frant

panel

red-

active

LED

green-

ready

flash-

error

SERIAL

BUS

POWER

ON

Figure

4.2

back

panel

Please9

don't

connect

anything

until

you've

completed

the

following

section9

otherwise

you

will

get

danger

or

take

trouble

in

your

system.

3.

INSTALLATION

CABLE

CONNECTIONS

First,

plug

the

power

cable

into

the

back

of

the

disk

drive.

It

won't

go.

in

if

you

try

to

put

it in

upside

down.

Next,

plug

the

other

end

into

the

electrical

outlet.

If

the

drive

makes

any

sound

at this

time,

turn

it

off

using

the

switch

on the

back!

Do

not

plug

any

other

cables

into

the

drive

with

the

power

on.

Second,

plug

the

serial

bus

cable

into

either

one

of

the

serial

bus

sockets

on

the

back

of

the

drive.

Turn

off

the

computer

and

plug

the

other

end

of

the

cable

into

the

back

of

the

computer.

You're

ready

to

go!

If

you

haveaprinter

or

another

disk

drive,

attach

its

cable

to

the

remaining

serial

bus

socket

to

"daisy

chain"

the

devices.

If

it'sadisk

drive,

you

will

need

to

change

one

of

the

drives

device

numbers.

TURNING

ON

THE

POWER

When

all

the

devices

are

hooked

together,

the

power

may

be

turned

on.

It is

importanttoturn

them

on

in

the

correct

order:

the

computerisalways

last.

Also:

make

sure

there

are

no

disks

in

the

disk

drive

when

you

turn

on

the

power.

DISK

INSERTION

To

insert

a

disk,

simply

turn

the

lever

to

a

horizontal

position,

slide

the

disk

in

gently

till

it

stops,

and

turn

the

lever

down.

The

disk

goes

in

face

up,

with

the

large

opening

going

in

first

and

the

write-protect

notch

(a

small

square

cutout

in

the

disk)

on

the

left.

Never

remove

a

disk

when

the

drive

light

is

on

i

And

remember,

always

remove

the

Disk

before

the

drive

is

turned

on

or

off!

Data

c^n

be

destroyed

by

the

drive

at

this

time!

4.

USING

PROGRAMS

USING

PREPACKAGED

PROGRAMS

If

you

want

to

useaprogram

already

writtenona

disk,

such

asavideo

game,

here's

all

you

have

to

do.

Turn

the

lever

up and

insert

the

preprogrammed

disk

so

the

label

on

the

disk

is

facing

up and

closest

to you.

There

should

be,alittle

notch

on

the

disk

(maybe

covered

with

tape)

that

should

be

on

the

left.

Turn

the

lever

down.

Now,

type

in

LOAD

"program

name"

and

hit

the

RETURN

key.

The

disk

will

make

noise

and

your

screen

will

say:

SEARCHING

FOR

PROGRAM

NAME

LOADING

READY

When

the

screen

says

READY,

just type

in

RUN

and

hit

the

RETURN

key-

your

program-isready

to

use!

LOAD

COMMAND

PURPOSE:

To

transferaprogram

from

the

disk

to

the

computer's

current

memory.

FORMAT:

LOAD"program

,ameM,

device

#,

command

#

The

program

name

is

a

character

string,

that

is,

either

a

name

in

quotes

or

the

contents

of

a

given

string

variable.

The

device

numberispreset

on the

disk

drive's

circuit

board

to

be

8.

If

you

have

more

than

one

drive,

read

the

chapteronchanging

the

device

number.

This

manual

assumes

you're

using8as

the

device

number

for

the

disk

drive.

The

command

numberisoptional.

If

not

given,

or

zero,

the

program

is

loaded

normally,

into

the

start

of

your

computer's

available

memory

for

BASIC

programs.

If

the

number

is

1,

the

program

will

be

loaded

into

exactly

the

same

memory

locations

from

which

it

cane.

The

command

number

1

is

used

mainly

for

machine

language,

character

sets,

and

other

memory

dependant

functions,

EXAMPLES:

LOAD

"TEST",8

LOAD

"Program

#1M,8

LOAD

"Mach

Lang",8,1

LOAD

A$,J,K

CAUTION:

Besides

putting

your

program

into

the

computer's

current

memory,

LOAD

wipes

out any

previous

program

there!

NOTE:

As

in

the

last

example,

you

can

use

variables

to

represent

strings,

device

numbers,

and

command

numbers;

just

be

sure

they

are

all

previously

defined

in

your

program*

Also,

see

the

note

on

file names

on

page

9*

THE

DISK

DIRECTORY

Your

disk

drive

is

a

random

access

device.

This

means

the

read/write

head

of

the

drive

can

go

to

any

spot

on

the

disk

and

accessasingle

block

of

data,

which

hold

up

to

256

bytes

of

information.

There

are

683

blocksona

disk.

Fortunately,

you

don't

have

to

worry

about

individual

blocks

of

data

(check

chapter5if

you

do).

There

isaprograminthe

disk

drive

called

the

Disk

Operating

System,orDOS,

that

keeps

track

of

the

blocks

for

you.

It

organizes

them

intoaBlock

Availibility

Nap,

or

BAM,

andadirectory. The

BAN

is

simply

a

checklistofthe

blocks,

and

is

updated

every

timeaprogram

is

SAVEd

oradata

file

OPENed.

The

directory

is

a

list

of

all

programs

and

other

files

stored

on

the

disk*

There

are

144

entries

available,

consisting

of

information

like

file

name

and

type,alist

of

blocks

used,

and

the

starting

block.

Like

the

BAN,

the

directoryisupdated

each

timeaprogramisSAVEd

or

a

file

OPENed.

However,

the

BAN

isn't

updated

until

the

file

is

CLOSEd.

If

not

CLOSEd

properly,

all

data

in

that

file

will

be

lost.

Nore

on

this

later.

The

directory

can

be

LOADed

into

your

computer

memory

just

likeaBASIC

program.

Put

the

disk

in

the

drive

and

type:

L0AD"$",8

The

computer will

say:

SEARCHING

FOR

$

FOUND

$

LOADING

READY

Now

the

directoryisin

current memory,

and

if

you

type

LIST

it

will

be

displayed

on

the

screen.

To

examine

the

directory

from

insideaBASIC

program,

see

chapter6concerning

the

GET#

statement.

PATTERN

MATCHING

AND WILD

CARDS

To

make

LOADing

easier,

pattern

matching

lets

you

specify

certain

letters

in

the

program

name

so

the

first

program

in

the

disk

that

matches

your

patternisthe

one

loaded.

EXAMPLES:

LOAD

"*",8

(LOADs

first

file

on

disk)

LOAD

"TE*",8

(LOADs

first

file

that

starts

with

TE)

LOAD

"TE??",8

(LOADs

first

file

that

has

four

letters

and

begins

with

TE)

LOAD

"T?NT",8

(LOADs

first

file

that

has

four

letters

but

could

be

TINT, TENT,

et

cetera)

The

asterisk

(*)

tells

the

computer

not

to

worry about

the

rest

of

the

name

while

the

question

mark

(?)

acts

asawild

card.

The

above

can

also

be

used

when

LOADing

the

directory

into

current

memory.

This

allows

checking

for

a

list

of

specific

programs.

The

procedure

is

the

same

as

above

except

for

the

additionofa

"$:"

:

EXAMPLE: LOAD

"$:T?ST*",8

(LOADs

all

file

names

in

the

directory

that

have

the

correct

first,

third,

and

fourth

letters)

SAVE

PURPOSE:

Transferaprogram

in

current

memory

onto

the

disk

for

later

use.

FORMAT:

SAVE"program

name",

device

#,

command

#

As

before,

the

command

number

is

optional.

If

there

is

alreadyaprogram

or file

by

the

same

name

on

the

disk

or

there

isn't

enough

room

on

the

disk,

an

error

signal

will

be

generated.

If

there

isn't

enough

room,

other

programs

will

have

to

be

erased

or

useadifferent

disk.

EXAMPLE:

SAVE

"HOMEWORK",8

SAVE

AND

REPLACE

PURPOSE:

Replaceanalready

existing

file

witharevised

version.

FORMAT:

SAVE"§0:program

name",8

If

you

edit

an

existing

program

and

want

to

save,itunder

the

same

name,

SAVE

AND

REPLACE

does

so

automatically.

If

you

want

to

keep

the

old

version,

save

the

new

version

underadifferent

name*

EXAMPLE:

SAVE"@0:HOMEWORK",8

VERIFY

PURPOSE:

Checks

current

program

with

one

on

the

disk.

FORMAT:

VERIFY"program

name",

device#,command

#

VERIFY

doesabyte

by

byte

comparison

of

the

program

in

current

memory

with

one

on

the

disk,

as

specifiedinthe

VERIFY

command.

EXAMPLE:

VERIFY"OLD

VERSION",8

NOTE

ABOUT

FILE

NAMES:

File

names

must

begin

with

a

letter

notanumber.

Spaces

are

permitted.

While

there

is

no

restrictiononthe

length

of

a

file

name,

all

commands

must

be

58

or

fewer

charactersinlength.

For

example,inthe

above

VERIFY

command,

there

are

10

characters

besides

the

actual

program

name,

so

the

maximum

name

length,inthis

case,

is

48

characters.

5,

DISK

COMMANDS

So

far,

you

have

learned

the

simple

ways

of

using

the

disk

drive.

In

order

to

communicate

more

fully

with

the

disk,

disk

commands

need

to

be

used.

Two

of

these,

OPEN

and

PRINT*,

allow

the

creation

and

fillingofa

data

file

on

the

disk.

Just

as

important

is

their

ability

to

openacommand

channel,

allowing

the

exchangeofinformation

between

computer

and

disk

drive.

OPEN

PURPOSE:

CreatesafilebyOPENingacommunication

channel

between

computer

and

disk

drive.

FORMAT:

OPEN

file#,deviceI,(command)

channel#,text

string

The

file

number

shouldbeany

number

from1to

127.

Numbers

from

128

to

255

can

be

used

but

shouldbeavoidedasthey

cause

the

PRINT#

statement

to

generatealinefeed

after

carriage

returns.

The

device

numberisusually

8.

The

channel

number

can

be

any

number from2to

15.

These

refertochannels

used

to

communicate

with

the

disk, and

channels

0

and1are

used

by

the

operating

system

for

LOADing

and

SAVEing.

Channels2through

14

can

be

used

to

send

data

to

files

while

15

is

reservedasthe

command

channel.

The

text

string

is

a

character

string

that

is

used

as

the

name

for

the

file

created.Afile

cannot

be

created

unless

the

file

name

is

specifiedinthe

text

string.

If

you

attempt

to

openafile

already

opened,

the

error

signal

"FILE

OPEN

ERROR"

will

be

generated.

10

EXAMPLES:

OPEN

5,8,5,

"TEST"

(createsafile

called

TEST)

OPEN

15,8,15,"I"

(sends

commandtodisk

on

command

channel)

OPEN

A,B,C,Z$

(these

variables

must

be

defined)

Fillsapreviously

OPENed

file

with

data.

PRINT#

file

!,

text

string

The

PRINT!

command

works

exactly

like

the

PRINT

command,

except

the

data goes

to

a

device

other

than

the

screen,

in

this

case

the

disk

drive.

When

used

withadata channel,

PRINT!

sends

informationtoa

buffer

in

the

disk

drive

which

then

LOADs

it

onto

the

disk.

When

used

withacommand

channel,

PRINT!

sends

commandstothe

disk

drive. The

commandisplaced

inside

quotes

as

a

text

string.

EXAMPLES:

PRINT!

7,C$

(fills

file7with

text

string

C$)

PRINT!

15,

"I"

(sends

disk

commandoncommand

(Channel)

INITIALIZE

PURPOSE:

Initializes

disk

driver

to

power

up

condition.

FORMAT:

OPEN

15,8,15,

"I"

or

OPEN

15,8,15:PRINTH5,

"I"

Sometimes,

an

error

condition

on

the

disk

will

prevent

you

from

performinganoperation.

INITIALIZE

returns

the

disk

drive

to

its

original

state

when

power

is

turned

on.

NEW

PURPOSE:

Formats

new

disk

or

re-formats

used

one.

FORMAT:

PRINT!15,

"NEW

0:

disk

name,

id!"

This

command

formatsanew

disk.

It

is

also

useful

to

erase

an

already-formatted

disk,

as

it

erases

the

entire

disk,

puts

timing

and

block

markers

on,

and

creates

the

directory

and

the

BAM.

The

disk

name

is

for

user

convenience

while

the

id!

isa2

digit

alphanumeric

identifier

that

is

placed

in

the

directory

and

every

block

on the

disk.

If

you

switch

disks

while

writing

data,

the

drive

will know

by

checking

the

id#.

EXAMPLES:

OPEN

15,8,15,

"NEW

0:

TEST

DISK,

Al"

OPEN

15,8,15:PRINT!15,"N0:'MYDISK,

MY"

11

If

the

disk

needs

erasing

but

not

re

forma11ing,•

the

same

command

is

used,

but

leave

out

the

id#.

EXAMPLE:

OPEN

15,8,15,"N0:

NEW

INFO11

SCRATCH

PURPOSE:

Eraseafile

or

files

from

the disk.

FORMAT:

PRINT#15,

"SCRATCH

0:

filename"

This

command

erases

one

or

more

files

from

the

disk,

making

room

for

new

or

longer

files.

Groups

of

files

can

be

erased

at

one time

by

naming

all

of

them

in

one

scratch

command.

EXAMPLES:

PRINT#15,"S0:TEXT"

(erases

file

called

TEXT)

PRINT#15,"SCRATCH0:

TEXT,

0:TEST,

0:

MUSIC"

(erases

files

TEXT,

TEST,

and

MUSIC)

COPY

PURPOSE:

Duplicateanexisting

file.

FORMAT:

PRINTi.15,

"COPY

0:newfilename=0:oldf

ilenar.e"

COPY

allows

you

to

makeacopy

of

any

programorfile

on

the

disk.

The

new file's

name

must

be.

different

from

the

old

one.

COPY

can

also

combineupto

four

files

into

one

new

one.

EXAMPLES:

PRINT#15,"C

0:BACKUP=0:ORIGINAL"

PRINT#15,"COPY0:NEWFILE=0:

OLD1,0:

OLD2,0"

(combines

OLD1

and

OLD2

into

NEWFILE)

RENAME

PURPOSE:

Change

the

name

of

existing

file.

FORMAT:

PRINT#15#"RENAMEO:

newname=0:

oldname"

This

command

lets

you

change

the

name

of

a

file

once

it's

in

the

disk

directory.

RENAME

will

not

work

on

any

files

that

are

currently

open.

EXAMPLE:

PRINT#15,HR

0:GOODNAME=0:

DUMBNAME"

VALIDATE

PURPOSE:

Removes

wasted

spaces

on

disk.

FORMAT:

OPEN

15,8,15,"V0:"

12

Afteradisk

has

-had

many

files

saved

and

erased,

small

gaps

in

the

data

begin

to

accumulate

and

waste

memory

space

on the

disk.

VALIDATE

reorganizes

your

disk

so

you

can

get

the

most

memory

from

the

available

space.

Also,

this

command

removes

files

that

were

OPENed

but

never

properly

CLOSEd.

CAUTION!

VALIDATE

erases

random

files

(see

chapter

7).

If

your

disk

contains

random

files,

DO

NOT

use

this

command!

READING

THE

ERROR

CHANNEL

Without

the

DOS

Support

Program,

there

is

no

way

to

read

the

disk

error

channel

since

you

need

to

use

the

INPUT#

command,

unusable

outsideaprogram.

Here

is

a

simple

BASIC

program

to

read

the

error

channel:

10

OPEN

15,8,15

20

INPUT#15,

A$,

B$,

C$,

D$

30

PRINT

A$,

B$,

C$,

D$

When

you

use

an

INPUT#

from

the

command

channel,

you

read

up

to

four

variables

that

describe

the

error

condition.

The

first,

third,

and

fourth

are

numberssonumberic

variables

can

be

used.

The

inputs

are

organizedasfollows:

First:

error

number

(0

means

no

error).

Second:

error

description.

Third:

track

number

where

error

occurred.

Fourth:

block

(sector)intrack

where

error

occurred.

Errors

on

track

18

concern

the

BAM and

directory.

CLOSE

PURPOSE:

Proper

allocationofdata

blocks,

closes

entry.

FORMAT:

CLOSE

file#

This

command

is

very

important.

Onceafile that

was

opened

is

no

longer

needed

for

data

entry,

IT.

MUST

BE

CLOSED

OR

ELSE

ALL

DATA

IN

THAT

FILE

WILL

BE

LOST.

It

is

very

important

that

the

data

filesbeCLOSEd

before

the

error

channel

(channel

#15)isCLOSEd,

Otherwise,

the

disk

drive

will

CLOSE

them

for

you

but

BASIC

will

still

think

they

are

open

and

let

you

try to

write

to

them.

The

error

channel

should

be

OPENed

first

and

CLOSEd

last

of all

your

files.

NOTE:

If

your

BASIC

program

leads

to

an

error

condition,

all

files

are

CLOSEdinBASIC,

but

not

on

the

disk

drive.

This

is

VERY

DANGEROUS!

Immediately

type:

CLOSE

15:

OPEN

15,8,15:

CLOSE

15

This

will

re-initialize

your

drive

and

make

all

your

files

safe.

13

6.

SEQUENTIAL

FILES

Sequential

files

are

stored

and

read

sequentially

from

beginningtoend.

There

are

basically

three

different

types

of

sequential

files

that

can

be

used.

The first

is

the

program

file,

which

is

abbreviatedinthe

directoryasPRG.

The

PRG

is

the

only

sequential

file

that

can

store

and

read

programs.

The

second

file,

sequential

(SEQ),

and

the

third

file,

user

(USR),

are

for

data

handling.

These

two

files

must

be

opened

just like

the

command

channelinthe

last

chapter.

OPEN

PURPOSE:

Openasequential

file.

FORMAT:

OPEN

filet,

device*,

channel*,

"0:

name,

type,

direction"

The

file

number

is

the

same

as

in

previous

uses

of

the

OPEN

command,

the

device

numberisusually8,the

channel

number

is

a

data

channel,2through

14.

It'sagood

idea

to

use

the

same

number

for

both

file

and

channel

numbers,

for

easy

remembering

(you

may

have

noticed

this

in

previous

examples).

The

name

is

the

file

name,

for

which

no

wild

cards

or

pattern

matching

may

be

used

if

you're

creatingawrite

file.

The

type

can

be

any

one

from

the

list

below,

or

at

least

the

first

letter

of

one.

The

direction

must

be

READ

or

WRITE,

or

at

least

their

first

letters.

FILE

TYPE

MEANING

PRG

Program

file

SEQ

Sequential

file

USR

User

file

REL

Relative

(not

implementedinBASIC

2.0)

EXAMPLES:

OPEN

5,8,5,

"0:

DATA,

S,

R"

OPEN

A,B,C,"0:TEXT,

P,W"

OPEN

A,B,C,"0:"

+A$+

"U,W"

(OPENsawrite

file

withaname

specifiedbythe

string

variable

A$)

OPEN

2,8,2

"(30:

PHONES,S,W"

(replaces

old

version

of

the

file

withanew

one)

Once

a

file

has

been

opened

for

reading

or

writing,

three

commands

can

be

used

to

actually

transfer

the

data.

These

commands

are

PRINT*, INPUT*r

and

GET#.

14

PRINT#

PURPOSE:

Directs

output

to

previously

opened

file.

FORMAT:

PRINT#

file#,

data

list

(no

space

allowed

between

PRINT

and

*)

The

PRINTf

statement

works

exactly

like

PRINT:

formatting

capabilities

for

punctuation

and

data

types

work

just

the

same.

But

that

means

you

need

to

be

careful

when

putting

data

into

files. The

file

numberisthe

one

just

OPENed

and

the

data

list

consistsofvariables

and/or^text

inside

quotation

marks.

Care

must

be

taken

when

writing

in

data

so

that

it

is

as

easy

as

possibletoread

out later.

Commas

used

to

separate

items

will

cause

spaces

to

be

stored

on

the

disk.

Semi-colons

will

keep

spaces

from

being

stored.

If

both

commas

and

semi-colons

are

absent,acarriage

return

(CR)

will

be

stored

at

the

end

of

the

data

that

is

written

in.

Consider,

the

following

example

program:

10

A$="THISISAH

20

B$="TEST"

30

OPEN

8,8,8,

"0:TEST

,S,W"

40

PRINT#8,A$,B$"OF

THE

DISK"

50

CLOSE8

60

END

If

you

could

see

the

data

and

its

positiononthe

disk,

it

would

look

like

this:

123

4 5 6

7 8 9

10

11

12 13

14

15

16

17

18 i9

20

21

22

23

24

25

THISISA

TESTOF

26

27

28

29

30 31

32

33

34 35

THE

DISKCR

eof

(end

of

file)

The

comma,

semi-colon,

and

carriage

return

have

special

meaning

when storedtothe

disk.

When

used

insideastring

or

quotes,

they

will

be

storedasregular

characters.

When

used

as

a

separator

between

fields,

the

comma

inserts

spaces

(usually

a

waste

of

memory),

the

semi-colon

doesn't,

and

the

CR stores

a

carriage

return

on

the

disk.

These

are

important

when

you

use

GET#

or

INPUT#toretrieve

the

data

you

stored•

GET»

PURPOSE:

To

get

data

from

the

disk

byte

by

byte,

FORMAT:

GET#

file

#,

variable

list

Data

comesinbytebybyte,

including

CR's,

commas,

and

other

separators.

Ge-nerally,

it's

safer

to

use

character

string

variablestoavoid

error

messages.

15

EXAMPLES:

GET#8,

A$

GET#5,.A(only

works

for

numerical

data)

GET#A,

B$,

C$,

D$

(GETs

more

than

one

variable

at

a

time)

The

GETf

statement

is

very

useful

when

the

actual

data

contentorstructureisnot

knownr

such

as

a

file

on

a

disk

that

has

been

damaged.

If

you

are

familiar

with

the

file

and

there

are

no

problems,

INPUT!ismore

efficient.

But

to

look

at

data

in

an

unfamiliarordamaged

file,

the

following example

program

will

read

the

contents

out

(in

this

case,

from

the

file

created

in

the

PRINTi

example

program).

10

OPEN

8,8,8,-

"TEST"

20

GET#8,A$:PRINT

A$;

30 IF

ST=0

THEN

20

(ST

isastatus

signal)

40

CLOSE

8

50

END

INPUT#

PURPOSE:

Retrieve

disk

data

in

groups.

FORMAT:

INPUT#

file

#,

variable

The

file

number

is

the

same

as

the

one

OPENed

and

the

variable

can

represent

character

strings

or

numbers.

To

read

a

group

of

data,

separators

are

needed

to

indicate

the

start

and

finish

of

the

group.

These

are

the

comma,

semi-colon,

and

CR,

and

work

as

explained

in

the

section

on

the

PRINT#

command.

Numbers

are

stored

withaspace

in

front

of

them,

which

is

empty

for

positive

numbers

and

containsanegative

sign

for

negative

numbers.

Here'sasample

program:

10

OPEN

8,8,8,"@0:

DATAFILE,S,W"

20

FOR

A=l

TO

10

30

PRINT#8,A

40

NEXT

A

50

CLOSE

8

60

OPEN

2,8,2,"DATAFILE"

70

INPUT#2,B:PRINT

B

80 IF

ST=0

THEN

70

90

CLOSE

2

100

END

This

example

program

will

write

the

numbers1through10to

a

sequential

file

called

DATAFILE.

Lines

70

and

80

will

read

the

data from

the

disk

and

print

it

out.

See

page

20

for

two

useful

sample

programs.

16

7.

RANDOM

FILES

Sequential

files

are

fine

when

you're

just

working

with

a

continuous

streamofdata,

but

some

jobs

need

more

flexibility.

For

example,

if

you

have

a

large

mailing

list,

it

would

be

inconvenient

to

scan

the

entire

list

to

find

one

person's

address.

A

random access

meth.od

would

let

you

pick

out

the

desired

data

without

having

to

read

the

whole

file.

There

are

two

file

types

that

can

do

this:

random

files

and

relative

files.

Random

files

are

the

best

choice

when

speed

is

a

desired

factor,

as

in

machine

language

programs.

This

is

because

locationsofthe

data

are

maintainedbythe

program

when

random

files

are

used,

while

relative

file

locations are

maintainedbythe

DOS.

The

problem

is

random

files

are

easy

to

accidentally

remove

from

the

disk

since

the

DOS

doesn't

maintain

them.

Random

files

are

files

that

have been

written

to

a

certain

physical

location

on

the

disk.

The

disk

is

divided

into

35

concentric

rings,

or

tracks,

with

each

track

containing

from

17

to

21

sectors.

TRACK

NUMBER

1

TO

17

18

TO

24

25

TO

30

31

TO

35

SECTOR

RANGE

0

TO

20

0

TO

18

0

TO

17

0

TO

16

TOTAL

SECTORS

21

19

18

17

It

is

possibletoread

and

write

to

any

block

on

the

disk,

as

well

as

determine

which

blocks

are

available

for

use.

The

following

commands

explain

howtouse

the

random

file

functions.

OPEN

PURPOSE:

OPENsadata

channel

for

random

access.

FORMAT:

OPEN

file

4,

device

#,

channel

#,

"#"

When

working

with

random

files, you

need

to

have

two

channels

open

to

the

disk:

the

command

channel

(15)

to

send

commands

and

a

data

channel(2to

14)

for the

data

transfer. The

data

channel

for

random

access

files

is

OPENed

by

selecting

the

pound

sign,

"#", as

the

file

name.

The

additional

n#"

on

the

end

of

the

command

causes

the

disk

to

allocatea256

byte

buffer

for

the

purposeofhandling

the

desired

block

of

data.

If

a

buffer

numberisspecified,

the

allocated

buffer

will

be

the

one

you

specified.

EXAMPLES:

OPEN

5,8,5,"#"

(you

don't

care

which

buffer)

OPEN

A,B,C,"#2lf

(you

specify

buffer

2)

17

BLOCK-READ

PURPOSE:

To

readaspecific

block

of

data

from

the

disk.

FORMAT:

PRINT!

file

#,"BLOCK-READ:"

channel

#,

drive

#,

track

!,

block#(BLOCK-READ

can

be

replaced

with

B-R)

The

file

and

channel

numbers

are

ones

that

have

been

OPENed.

The

track

number

and

block

number

indicate

which

256

byte

block

is

to

be

read.

Executing

this

command

causes

the

disk

drive

to

move

the

specified

block

of

data

into

the

buffer

area.

The

data

can

then

be

read

from

the

buffer

area

using

either

INPUT!

or

GET#.

Only

data

in

that

particular

block

will

be

read,

and

any

unused

bytes

in

the

block

will

not

be

read*

The

sample

program

below

uses

BLOCK-READtoread

the

contents

of

block9on

track

5

and

display

the

block's

contents

on

the

screen.

10

OPEN

15f8r15

20

OPEN

8,8,8,"!"

30

PRINT!15,

"B-R:"8,0f5,9

(reads

block

into

buffer)

40

GET!8,

A$

50

PRINT

A$;

60

IF

ST=0

THEN

40

70

PRINT

"READ.

COMPLETE"

80

CLOSE8:

CLOSE

15

.BLOCK-WRITE

PURPOSE:

Writeablock

of.data

to

a

specified

block

location

on

the

disk.

FORMAT:

PRINT!

file

#,

"BLOCK-WRITE:11

drive

#,

channel

!,

track

!,

block

!

BLOCK-WRITE

can

be

shortened

to

B-W.

This

command

causes

data

previously

stored

in

the

buffer

to

be

written

to

the

specified

locationonthe

disk.

The

data

should

be

transferred

to

the

buffer

on

a

data

channel

using

PRINT!

before

BLOCK-WRITEingitinto

the

disk.

The

DOS

keeps

track

of

how

many

bytes

are

stored

into

the

buffer and

stores

the

byte

count into

the

first

byte

of

the

block

when

BLOCK-WRITEisexecuted. This

means

that

only

255

bytes

can

actually

be

writtentoor

read

from

the

block,

since

the

byte

count

uses

the

first

byte

of

the

block.

Here's

an

example

of

a

routine

that

will

write

data

to

the

same

block

that

is

read

in

the

BLOCK-READ

example

above

(track

5,

block

9):

10

OPEN

15,8,15

20

OPEN

8,8,8,"!"

30

FOR

AA=1 TO

32

40

PRINT!8,

"TESTING"

50

NEXT

60

PRINT!15f"B-W:"

8;0>5,9

70

CLOSE8:CLOSE15

18

BLOCK-ALLOCATE

PURPOSE:

Determine

if a

particular

block

is

free

and

allocate

it

if

so.

FORMAT:

PRINT#15,"B-A:"

channel

#,drive#,track

»,

block

*

As

mentioned

earlier,

the

DOS

does

not

maintain

the

disk

when

BLOCK-READs

and

BLOCK-WRITEs

are

used.

But

the

user

can

make

sureaparticular

block

is

availablebyusing

the

BLOCK-ALLOCATE

command.

This

allows

use

of

BLOCK

commands

on

a

disk

with

files

already

on

it.

By

checking

the

BAM,

the

command

aetermines

if

the

specified

block

has

been

used.

Since

the

BAM

updates

each

time

a

file

is

stored

on

the

disk,

files

can

be

maintained.

BLOCK

commands

do

not

update

the

BAM

and

so

will

not

be

recognized

unlessaBLOCK-ALLOCATE

has

been

executed.

CAUTION:

the

VALIDATE

command

does

not

recognize

random

files

and

should

never

be

used

on

a

disk

that

has

random

files.

If

BLOCK-ALLOCATE

determines

that

the

specified

block

has

already

been

used,

an

error

signal

(65)

will

be

generated.

The

error

message

tells

you

the

numbers

of

the

next

available

track

and block

on

the

disk.

This

block

does

not

get

allocated,sothe

BLOCK-ALLOCATE command

must

be

used

again,

but

this

time

you

can

be

sure

that

the

block

specifiedisfree

to

use.

The

following

program

will

allocateablock

and

write

to

that

block.

If

the

block

is

already

used,

it

will write

to

the

next

available

one,

as

indicatedbythe

error

message.

c

10

OPEN

15,8,15:OPEN

8,8,8,"#"

20

PRINT#8,"THIS

GOES

INTO

THE

BUFFER"

30

T=5:S=9

40

PRINT#15,"B-A:M0,T,S

50

INPUT#15,A,A$,B,C

60

IF

A=65

THEN

T=B:S=C:

GOTO

40

70

PRINT#15,"B-W:"

8,0,T,S

80

PRINT"DATA

WAS

STORED

IN

TRACK:"T,"

SECTOR:"S

90

CLOSE

8:CLOSE

15

100

END

Line

20

loads

the

buffer

with

text,

lines

30

and

40

check

block9on

track5to

see

if

it's

free,

and

line

50

inputs

the

error

signal.

If

the

block

is

free,

the

data

is

stored

there.

If

block9on

track

5

is

already

used,

line

60

takes

the

new

block

and

track

numbers

and

allocates

the

block

they

specify,

and

then

the

data

is

storedinthe

new

block.

Lines70and

80

read

the

track

and

b]ock

numbers

into

the

computer

and

print

them

on

the

screen.

19

8.

RELATIVE

FILES

Relative

files

can

access

any

piece

of

data

on

the

disk,

just

like

random

files,

but

you

don't

have

to

maintain

the

files

in

your

own

program*

The

DOS

maintains

the

data

for

you,

keeping

track

of

the

status

of

your

files.

Because

of

this,

relative

files

are

slower

than

random

files,

but

often

the

extra

convenience

makes

up

for

this.

The

DOS

keeps

track

of

the

tracks

and

sectors

(blocks)

used,

and

even

allows

records

to

overlap

from

one

block

to

the next.

It

does

this

be

establishing

side

sectors,aseries

of

pointers

for

the

beginningofeach

record.

There

can

be6side

sectors

in

a

file,

and

each

side

sector

can

point

to

up

to

120

records.

This

meansafile

can

have

as

many

as

'720

records,

and

since

each

record

can

be

254

characters

long,

one

file

can

fill

the

entire

disk.

The

block

format

consistsofthe

first

two

bytes

specifying

the

track

and

sector

of

the next

data

block.

The

next

254

bytes

contain

the

actual

data.

Any

empty

record

will

have

FF

(hexidecimal

for

all

l's)

in

the

first

byte

and

00

in

the

rest

of

the

record.

The

side

sectors

are

used

to

reference

all

side

sector

locations,

not

just

the

120

data

block

locations

related

to

that

side

sector.

On

the

next

page

you

will

find

a

chart

showing

the

format

of the

relative

files.

20

RELATIVE

FILE

FORMAT

DATA

BLOCK:

BYTE

DEFINITION

0,1

...••..

Track

and

sector

of

next

data

block.

2-256

254

bytesofdata.

Bipty

records

contain FF

(all

binary

ones)

in

the

first

byte

followedby00

to

the

end

of

the

record.

Partially

filled

records

are

padded

with

nulls

(00).

SIDE

SECTOR

BLOCK:

BYTE

DEFINITION

0,1

••

Track

and

sectorofnext

side

sector

block.

2

Side

sector

number

(0-5).

3

••«•••••

Record

length.

4,5

Track

and

sectoroffirst

side

sector

(0).

6,7

Track

and

sectorofsecond

side

sector

(1),

8,9

Track

and

sectorofthird

side

sector

(2).

10,11

Track

and

sectoroffourth

side

sector

(3).

12,13

Track

and

sectoroffifth

side

sector

(4).

14,15

Track

and

sectorofsixth

side

sector

(5).

16-256

Track

and

sector

pointersto120

data

blocks.

USING

RELATIVE

FILES

Relative

files

are

created

the

first

time

they

are

OPENed.

That same

file

will

be

used

until

it

is

C LOS

Ed.

A

relative

file

can

only

be

erased fromadisk

by

using

the

SCRATCH

command

or

by

re-formatting

the

entire

disk.

The

"§"

sign,

used

with

SAVE

as

a

SAVE

and

REPLACE,

will

not

work with

relative

files.

FORMAT TO

CREATE

RELATIVE

FILE:

OPEN

file

#,

device#,channel#,"0:name,L,"♦CHR$(rl#)

(record

length)

21

EXAMPLES:

OPEN

2,8,2,"0:FILE,L"+CHR$(100)

(record

length

is

100)

OPEN

F,8,F,"0:"

+A$+

",L,"+CHR$(Q)

FORMAT

TO

OPEN

EXISTING

RELATIVE

FILE:

OPEN

file

#,

device#,channel#,w0:name"

EXAMPLE:

OPEN

2,8,6,

"0:

TEST"

V

In

this

case,

the

DOS

can

tell

by

the

syntax

that

it

is a

relative

file.

Both

of

the

above

formats

allow

either

reading

or

writingtothe

file.

HOWEVER:

In

order

to

read

or

write,

BEFORE

ANY

OPERATION,

you

must

position

the

file

pointe'r

to

the

correct

record

position*

POSITION

PURPOSE:

To

POSITION

the

file

pointerata

record.

FORMAT:

PRINT*

file#,"P"

CHR$(channel*)CHR$(rec#

lo)

CHR$(rec#

hi*)CHR$(record

position)

NOTE:

CHR$(record

position)

specifies

the

location

within

the

record

itself

and

is

optional.

Since

there

are

720

records

available

and

the

largest

number

one

byte

can hold

is

256,

two

bytes

must

be

used

to

specify

the

position.

The

rec#lo

contains

the

least

significant

part

of

the

address

and

reclhi

hold

the

most

significant.

The

relationship

is

represented

by:

reel*rec#hi*256♦rec#lo.

The

rec#

is

the

actual

positionina

record

where

data

transfer

starts.

EXAMPLES:

PRINTI15,"PHCHR$(2)CHR$(1)CHR$(0)

PRINTI15,"PWCHR$(CH)CHR$(Rl)CHR$(R2)CHR$(P)

Here'sasample

program

that

createsarelative

file:

10

OPEN

15,8,15

20

OPEN

8,8,8,"0:TEST,L,w+CHR$(50)

30

PRINT#15,ttP"CHR$(8)CHR$(0)CHR$(4)CHR$(l)

40

PRINT#8,CHR$(255)

50

CLOSE8:CLOSE15

22

This

program

createsarelative

file

called

TEST

that

will

contain

records

that

are

50

bytes

long.

Line

30

moves

the

pointertothe

first

positioninrecord

#1024

(rec#=256*4+0

=

JL024).

Notice

that

the

POINTER

commandissent

on the

command

channel

while

data

is

sent

on

a

data

channel,8in

this

case.

Since

the

record

didn't

already

exist,

an

error

message

will

be

generated,

warning

you

not

to

use

GET#

or

INPUT#.

Oncearelative

file

exists,

you

can

OPEN

it

and

expand

it

or

access

it

for

data

transfer.

The

file

can

be

expanded

but

the

record

length

cannotbechanged.

To

expandafile

just

specify

a

larger

number

of

records,asin

Line

30

in

the

previous

example

program.

To

write

data

to

an

existing

relative

file

use

the

following:

10

OPEN

15,8,15

20

OPEN

2,8,6,"0:TEST"

30

GOSUB

1000

40

IF

A=100

THEN

STOP

50

PRINT#15,MP"CHR$(6)CHR$(100)CHR$(0)CHR$(l)

60

GOSUB

1000

70

IF

A=50

THEN

PRINT#2,1:GOTO50

80

IF

A=100

THEN

STOP

90

PRINT#2,"123456789"

100

PRINT#15,"P"CHR$(6)CHR$(100)CHR$(0)CHR$(20)

110

PRINT#2,

"JOHN

QWERTY"

120

CLOSE

2:CLOSE15

130

END

1000

INPUT#15,A,A$,B$,C$

1010

IF

(A=50)OR(A<20)

THEN

RETURN

1020

PRINT

"FATAL

ERROR:";

1030

PRINT

A,A$,B$,C$

1040

A=100:RETURN

Lines

10

and

20

open

the

command

andadata

channel.

Lines

30

and

40

check

for

errors.

Line

50

moves

the

file

pointer

to the

100th

record

position.

Since

no

records

exist

yet,

an

error

signal

is

generated.

Lines

60,

70,

and

80

check

for the

error

and

create

100

records.

Line

90

writes9bytes

of

data

to

the

first9locations

in

record

100.

Line

110

then

printsaname

from

that

position.

It

is

important

that

data

is

wrltt.en

into

the

record

sequentiallysodata

alreadyinthe

recordisnot

destroyed.

23

The

following

program

reads

back

the

data

put

in

the

file

by

the

previous

program.

10

OPEN

15,8,15

20

OPEN

2,8,6,"0:TEST"

30

GOSUB

1000

r

40

IF

A*=100

THEN

STOP

50

PRINT#15,"P"CHR$(6)CHR$(100)CHR$(0)CHR$(l)

60

GOSUB

1000

70

IF

A=50

THEN

PRINT

A$

80 IP

A=100

THEN

STOP

90

INPUT!2,D$:

PRINT

D$

100

PRINT#15,"P"CHR$(6)CHR$(100)CHR$(0)CHR$(20)

110

INPUT#2,E$:

PRINT

E$

120

CLOSE

2:CLOSE15

130

END

1000

INPUT#15,A,A$,B$,C$

1010

IF

(A=5O)OR(A<20)

THEN

RETURN

1020

PRINT

"FATAL

ERROR:";

1030

PRINT

A,A$,B$,C$

1040

A=*100:

RETURN

Lines

90,

100,

and

110

read

the

record

and

display

the

contentsonthe

screen.

Notice

that

the

carriage

return

sent

to

the

disk

after

each

PRINT#

statementonthe

write

routineisthe

separator

for

each

field

on

the

record.

If

the

file

is

to

be

writtenorread

sequentially,itisn't

necessary

to

adjust

the

pointer

to

each

record.

The

record

pointer

automatically

starts

at

Position1if

no

other

position

has

been

defined.

The

pointer

moves

through

the

record

as

each

field

is

readorwritten.

24

9,

PROGRAMMING

THE

DISK

CONTROLLER

The

FSD-2isa

smart

peripheral,

which

means

that

it

contains

its

own

microprocessor

and

memory. An

advanced

programmer

can

access the

microprocessor

and

its

memory,

providingawide

range

of

applications.

Routines

can

be

designed

that

resideinthe

disk

memory

and

operateonthe

microprocessortocontrol

disk

drive

operation.

DOS

programs

can

be

added

that

come

from

the

actual

disk.

There

is

16K

of

ROM

in

the

disk

drive

as

well

as

2K

RAM.

The/

most

useful

area

to

the

advanced

programmer

is

the

buffer

RAJ^SfS*

area

located

between

4000H

and

5FFFH

(theHmeans

it's

^^^W'

hexadecimal

number).

This

area

can

actuallybewritten

into

witri

Machine

Language

level

instructions

and

executed

by

the

disk

controller

(microprocessor).

%

The

methodofhandling

data

transferstoand

from

memory

are

referred

to

as

MEMORY

commands.

There

are

three

basic

MEMORY

commands,

and

some

additional

commands called

USER

commands.

MEMORY-WRITE

PURPOSE:

Transfersupto

34

bytes

of

data

to

drive

memory.

FORMAT:

PRINT#15,"M-W:"CHR$(address

low

byte)

CHR$(address

high

byte)CHR$(#ofcharacters)

CHR$(data)

MEMORY-WRITE

allows

you

to

write

up

to

34

bytes

of

data

at

a

time

into

the

disk

controller's

memory.

MEMORY-EXECUTE

AND

USER

commands

can

be

used

to

run

this

code.

The

low

and

high

bytes

are

the

decimal

equivalent

of

the

hexadecimal

address

in

the

actual

memory

space.

The

number

of

bytes

is

the

decimal

amount

of

bytes

to

be

transferred,upto

34.

The

d^ata

must

be

the

decimal

representationofthe

hexadecimal-coded

instruction

you

wish

sent.

See

the

example

below.

10

OPEN

15,8,15

20

PRINT#i5,"M-W:"CHR$(0)CHR$(112)CHR$(3)CHR$(169)CHR$(8)CHR$(96)

30

CLOSE

15

This

routine

writes

three

bytes

to

locations

7000H,

7001H,

and

7002H

(256*112+0=28672=7000H).

The

three bytes

are:

169

(A9H,aPAGE

ZERO

instruction),

8

(8H,alocation),

96

(60H,aRETURN

instruction).

When

executed,

this

program

would

cause

the

drive

controllertoload

its

accumulator

with

the

contentsoflocation

0008H

and

then

return

control

back

to

the

disk

drive.

25

MEMORY-READ

PURPOSE:

Read

data

from

drive

memory.

FORMAT:

PRINT#15

file

#,

-M-R:"

CHR$(address

low

byte)

CHR$(address

high

byte)

The

MEMORY-READ

command

selectsabyte

to

be

read from

a

location

in

the

disk

drive

memory,

specified

by

the

low

and

high

bytes

of

the

location

address.

The

next

byte

read

(using

GET#)

from

channel

#15

will

be

from

the

specified

memory

location.

The

following

example

illustrates

this

by

reading

data from

10

consecutive

bytes,

located

from

FFOOH

to

FFOAH

(in

decimal,

65280

to

'65290).

10

OPEN

15,8,15

20

FOR A

=

1

TO

10

30

PRINT#15,"M-R:"CHR$(A)CHR$(255)

40

GET#15,A$:PRINT

ASC(A$♦CHR$(0));

50

NEXT

60

CLOSE

15

When

using

MEMORY-READ,

any

use

of

INPUT#

on

the

error

channel

will

give

peculiar

results.

This

can

be

clearedupby

using

any

other

command,

except

the

MEMORY

commands.

Here's

a

useful

program

that

reads

the

disk

controller's

memory:

10

OPEN

15,8,15

20

INPUT-LOCATION

PLEASE";A

30

Al

=

INT(A/256):A2=A-Al*256

40

PRINT#15,"M-R:"CHR$(A2)CHR$(A1)

50

FORL=

1

TO

5

.

60

GET#15,A$

70

PRINT

ASC(A$+CHR$(0))

80

NEXT

90

INPUT-CONTINUE-;A$

100 IF

LEFT$(A$,1)«"Y"

THEN

50

110

GOTO

20

MEMORY-EXECUTE

PURPOSE:

Executes

program

in

disk

memory.

FORMAT:

PRINT!15

file

*9-M-E:"CHR$(address

low

byte)

CHR$(address

high

byte)

Once

a

program

has

been

loaded

into

disk

memory

(either

the

16K

in

the

ROM

or

the

2K

in

the

RAM),

the

address

of

the

MEMORY-

EXECUTE

command

specifies

where

program

execution

will

begin.

The

use

of

this

commmand

requires

that

the

programtobe

executed

end

with

an

RTS

instruction,socontrol

will

be

returned

to the

DOS.

Following

is

a

routine

that

writes

an

RTS

(ReTurn

from

Subroutine).

26

10

OPEN

15,8,15,"M-W:"CHR$(0)CHR$(5);l;CHR$(96)

20

PRINT#15,"M-E:"CHR$(0)CHR$(19):

REM

JUMPS

TO

BYTE,

RETURNS

30

CLOSE

15

USER

COMMANDS

Along

with

the

USER1

and

USER2

commands

discussed

in

chapter

7f

there

are

others

that,

when

executed,

cause

jumps

to

specific

locations

in

the

disk

drive's

buffer.

This

lets

you

make

longer

routines

that

operate

in

the

disk's memory

along

withajump

table,

even

in

BASIC.

USER

COMMAND

FUNCTION

Ul

or

UA

BLOCK-READ

without

changing

buffer-pointer

U2

or

UB

BLOCK-WRITE

without

changing

buffer-pointer

U3

or

UC

jump

to

0500H

U4

or

UD

jump

to

0503H

U5

or

UE

jump

to

0506H

U6

or

UP

jump

to

0509H

U7

or

UG

jump

to

050CH

U8

or

UH

jumpto050FH

U9

or

UI

jump

to

FFFAH

U;

or

UJ

power-up

vector

UI+

set

Commodore64speed

U-

set

VIC

20

speed

EXAMPLESOFUSER

COMMANDS

PRINT#1S,"U3"

PRINT#15,"U"+CHR$(50+Q)

PRINT#15,"UI"

27

10-1.

CHANGING

THE

DEVICE

NUMBER

All

peripherals

need

device

numbers

so

the

computer

can

identify

which

one

you

want

to

transfer

data

to

or

from.

The

FSD-2

is

preset

inside

the

hardware

withadevice

number

of

8,

drive

number

0.

The

disk

knows

its

own device

number

by

looking

at

a

hardware

jumperonthe

circuit

board

and

writing

the

number

based

on

the

jumper

intoasection

of

its

RAN*

The

device

number,canbechanged

by

two

methods,

hardware

and

software.

If

you

are

temporarily

using

two

disk

drives,

using

the

software

method

lets

you

change

one

drive's

device

number

temporarily.

If

you

expect

to

use

two

(or

more)

drives

on

a

permanent

basis,

the

hardware

method

is a

simple

and

permanent

way

to

changeadrive's

device

number.

SOFTWARE

METHOD

The

device

number

is

changed

by

performingaMEMORY-WRITE

to

locations

0077H

and

0078H.

The

command

is

executed

once

the

command

channel

has

been

opened.

FORMAT:

PRINT#

file#,"M-W:

"CHR$(119)CHR$(0)CHR$(2)

CHR$

(address+32)CHR$(address+64)

The

addressisthe

new

device

number

desired.

Belowisan

exampleofchanging

the

device

numberto9.

10

OPEN

15,8,15

20

PRINT#15,"M-W:"CHR$(119)CHR$(0)CHR$(2)CHR$(9+32)CHR$(9+64)

30

CLOSE

15

First,

turn

on

one

drive

and

change

its

device

number,

then

the

next

drive,

until

all

the

drives

are

on.

28

10-2.

CHANGING

THE

DEVICE

NUMBER

All

peripherals

need

device

numbers

so

the

computer

can

identify

which

one

you

want

to

transfer

data

to

or

from.

The

FSD-2sdevice

number

is

extremely

easy

to

change.

No

hardware

or

software

modifications

are

needed.

Just

set

the

DIP

switches

on

the

bottom

of

the

drive

to

change

the

drive's

device

number.

Detailed

instructions

are

below.

TO

CHANGE

THE

DEVICE

NUMBER:

1.

TURN

OFF

DISK

DRIVE.

2.

TURN

OVER

AND

LOCATE

TWO

SMALL

DIP

SWITCHES

ABOUT

HALFWAY

TOWARDS

THE

BACK.

3.

SET

SWITCHES

IN

COMBINATION

WHICH

GIVES

DESIRED

DEVICE

NUMBER.

"ON"

IS

TOWARDS

THE

BACK

OF

THE

DRIVE.

DEVICE

NUMBER

SELECTED

BY:

DEVICE

NUMBER:

8

9

10

11

SWITCH

1:

ON

OFF ON OFF

SWITCH

2:

ON

ON

OFF

OFF

4.

DISK

DRIVE

IS

NOW

READY TO

USE

WITH

NEW

DEVICE

NUMBER.

29

APPENDIX

B.

DESCRIPTION

OF

ERROR

MESSAGES

Whenever

an

error

signal

is

generated,

the

LED light

on

the

front

panel

of

the

'FSD-2

will

start

flashing.

The disk

drive

will

not

send

the

error

message

to

the

computer

unless

requested.

The

following

routine

inputs

the

error

message

and

prints

it

on

the

computer's

screen.

10

OPEN

15,8,5

20

INPUT#15,A,A$,B$,C$

30

PRINT A,A$,B$,C$

40

CLOSE

15

50

END

Below

isalist

and

explanationofthe

error

messages

used

on

the

FSD-2

Disk Drive:

0:

NO

ERROR

This

is

not

an

indication

of an

error

and

will

occur

when

the

error

channel

is

read

while

the

LED

isn't

flashing.

1:

FILES

SCRATCHED

This

also

is

not

an

error

condition.

Reading

the

error

channel

after

one

or

more

files

have

been

scratched

will

show

this,aswell

as

the

number

of

files

that

have

been

scratched.

2-19:

UNUSED

ERROR

MESSAGE

NUMBERS

20:

READ

ERROR

(block

header

not

found)

The

disk

controller

is

unable

to

locate

the

header

of

the

requested

block.

This

can

be

caused

byabad

header

on

the

disk

or

specifyinganillegal

sector

number.

21:

READ

ERROR

(no

sync

character)

The

disk

controllerisunable

to

detectasync

mark

on

the

desired

track.

Caused

by

misalignmentofthe

read/

write

head

or

disk

not

present,

unformatted,

or

not

seated

properly.

Can

also

indicateahardware

failure.

22:

READ

ERROR

(data

block

not

present)

The

disk

controller

has

been

requestedtoread

or

verify

a

data

block

that

was

not

properly

written.

This

error

message

occurs

in

conjunction

with

the

BLOCK

commands

and

indicatesanillegal

track

and/or

sector

request.

23:

READ

ERROR

(checksum

error

in

data

block)

This

error

message

indicates

that

there

is

an

error

in

one

or

more

of

the

data

bytes.

The

data

has

been

read

into

the DOS

memory,

but

the

checksum

over

the

data

is

in

error. May

also

indicate

grounding

problems.

30

24:

READ ERROR

(byte

decoding

error)

The

data

or

header

has

been read into

the

DOS

memory,

butahardware

error

has

been

created

due

to

an

invalid

bit

patterninthe

data

byte.

May

also

indicate

grounding

problems.

25:

WRITE

ERROR

(write-verify

error)

This

messageisgeneratedifthe

controller

detects

a

mismatch

between

the

written

data

and

data

in

the

DOS

memory.

26:

WRITE

PROTECT

ON

The

controller

has been

requestedtowriteadata

block

while

the

write

protect

switchisdepressed.

Typically,

this

is

causedbyusingadisk

withawrite

protect

tab

over

the

notch.

27:

READ

ERROR

(checksum

error

in

header)

Thereisan

errorinthe

headerofthe

requested

data

block.

The

block

has not

been

read

into

the

DOS

memory.

May

also

indicate

grounding

problems.

28:

WRITE

ERROR

(long

data

block)

The

controller

attemptstodetect

the

sync

mark

of

the

next

header

after

writingadata

block.

If

the

sync

mark

does

not

appear

withinapre-determined

time,

the

error

messageisgenerated.

The

error

is

caused

by

a

bad

disk

format

(data

extends

into

the

next block)orby

a

hardware

failure.

29:

DISK

ID

MISMATCH

The

controller

has

been

requestedtoaccessadisk

which

has

not

been

initializedorhasabad

header.

Also

occurs

if

disks

are

switched

during

data

transfer.

30:

SYNTAX

ERROR

(general

syntax)

The

DOS

cannot

interpret

the

command

sent

to

the

command

channel.

Typically,

this

is

caused

by

an

illegal

number

of

file

names

or

patterns

are

illegally

used.

31:

SYNTAX

ERROR

(invalid

command)

The

DOS

doesn't

recognize

the

command.

The

command

must

start

in

the

first

position.

32:

SYNTAX

ERROR

(long

line)

The

command

sent

is

longer

than

58

characters.

33:

SYNTAX

ERROR

(invalid

file

name)

Pattern

matchingisused

invalidlyinthe

OPEN

or

SAVE

command.

31

34:

SYNTAX

ERROR

(no

file

given)

The

file

name

was

left

out

of

a

command

or

the DOS

does

not

recognize

it

as

such.

Typically,acolon

(:)

has

been

omitted.

35-38:

NOT

USED

39:

SYNTAX

ERROR

(invalid

command)

May

resultifthe

command

sent

to

the

command channel

is

unrecognizablebythe

DOS.

40-49:

NOT

USED

50:

RECORD

NOT

PRESENT

Result'ofdisk

reading

past

the

last

record

through

the

INPUT*

or

GET#

commands.

This

message

will

also

occur

after

positioningtoa

record

beyond

the

end

of

a

file

inarelative

file.

If

the

intentisto

expand

the

file

by

adding

the

new

record

(withaPRINT#

command),

the

error

message

may

be

ignored.

INPUT

or

GET

should

not

be

used

after

this

error

occurs

without

first

repositioning.

51:

OVERFLOW

IN

RECORD

PRINT*

statement

exceeds

the

record

boundary,

truncating

information.

Since

the

carriage

return,

sent

as

a

record

terminator,iscountedinthe

record

size,

this

message

will

occur

if

the

total

charactersinthe

record

(including

the

final

carriage

return)

exceeds

the

defined

size*

52:

FILE TOO

LARGE

Record

position

within

a

relative

file

indicates

that

disk

overflow

will

result.

53-59:

NOT

USED

60:

WRITE

FILE

NOT

OPEN

A

write

file

that

has

not

been closed

is

being

opened

for

reading.

61:

FILE

NOT

OPEN

A

file

being

accessed

has

not

been

opened

in

the

DOS.

Sometimesinthis

situation,anerror

is

not

generated,

the

requestissimply

ignored.

62:

FILE

NOT

FOUND

The

requested

file

doesn't

exist

on the

indicated

drive.

63:

FILE

EXISTS

The

file

name

of

the

file

being

created

already

exists

on

the

disk.

32

64:

FILE

TYPE

MISMATCH

The

file

type

does

not

match

the

file

type

in

the

directory

entry

for

the

requested

file.

65:

NO

BLOCK

Occurs

whenablock

to

be

allocated

has

already

been

allocated.

The

parameters

indicate

the

track

and

sector

available

with

the'

next

highest

number.

If

the

parameters

are

zero,

then

all

blocks

higher

in

number

are

in

use.

66:

ILLEGAL

TRACK

AND

SECTOR

The

DOS has

attemptedtoaccessatrack

or

sector

which

does

not

exist

in

the

format

being

used.

May

indicate

a

problem

reading

the

pointer

to the

next

block.

67:

ILLEGAL

SYTEM

TORS

This

special

error

indicatesanillegal

sytem

track

or

sector.

68,69:

NOT

USED

70:

NO

CHANNEL

(available)

The

requested

channelisnot

available,orall

channels

are

in

use.

A

maximumoffive

sequential

files

may

be

openedatone

time

to

the DOS.

Direct

access

channels

may

have

six

opened

files.

71:

DIRECTORY

ERROR

The BAM

(Block

Availability

Map)

does

not

match

the

internal

count.

There

is

a

problem

in

the

BAN

allocationorthe

BAM has

been

overwritteninDOS

memory.

To

correct

this

problem,

reinitialize

the

disk

to

restore

the

BAM

in

memory. Some active

files

may

be

terminatedbythe

corrective

action.

72:

DISK

FULL

Either

the

blocks

on

the

disk

are

used

up

or

the

directoryisat

its

limit

of

144

entries.

73:

DOS

MISMATCH

DOS1and2are

read

compatible

but

not

write

compatible.

Disks

may

be

interchangeably

read

with

either

DOS,

butadisk

formattedonone

version

cannot

be

written

upon

with

the

other

version because

the

formatisdifferent.

This

error

is

displayed

whenever

an

attemptismade

to

write

uponadisk

which

has

been

formattedina

non-compatible

format.

This

message

may

also

appear

after

power

up.

74:

DRIVE

NOT

READY

An

attempt

has

been

made

to

access

the

disk

drive

when

there

isn'tadisk

in

the

drive.

33