Service manual

ManualsBrandsZenith ManualsComputer equipmentSM-Z-90

WARNING

Insert

the

Hit

return

4-

16

1

DOUBLE-DENSITY

DISK

CONTROLl.ER

The

first speed to be tested is 30 milliseconds

per

track.

The

program

will

attempt

faster

step rates of

20,

12,

and

6 milliseconds

until

it has determined

your

drive's fastest

reliable seek time. As

it

tests,

the

program will

print

what

speed

it

is attempting.

For

each

successful pass, TEST will

print

the

message "OK!" to indicate

that

the

drive performs

reliably at

that

speed.

When

the

seek time test is complete,

the

message "Drive performs reliably

at

nn

mil-

liseconds

per

track" will

be

printed,

where

"nn"

is

the

optimum

seek

time

of

your

drive.

Record this

number

for future reference.

Note

that

if

TEST attempts a pass at 6 milliseconds

per

track, it may

not

print

the

"Drive

performs reliably... " message,

but

instead

may

simply

stop execution.

If

the

test attempts

a speed of

6 milliseconds

per

track

but

fails to

print

the

"Drive performs reliably... "

message,

then

the

fastest reliable seek

time

is

12

milliseconds

per

track.

If

the

test stops

executing

without

printing

any

message,

type

CfRL-C before you proceed to

the

next

test.

You willprobably

want

to perform

this

test

on

your otherdrives

in

order

to

determine

the

seekspeed for all drives

in

the

system. To

do

this, use the

"Switch"

TEST

menu

option

to

change

the

driveto

be

tested;

then

run

the

seektimetest again. Set your operating system

seek speed

to

that

of

the

slowest drive

in

your

system

unless

it

has

the

ability

to

use

different speeds for different drives.

A-ALIGN

NOTE: This procedure is for authorized service personnel only. Unauthorized

use

may

void your drive warranty.

The

Align

menu

option is

used

to

align

the

disk drive read/write head. To

use

this

option

you will need

an

alignment

diskette

and

a dual-trace oscilloscope

with

algebraic add.

This option causes

the

disk drive read/write head to select a track on

the

disk

which

you

specify.

The

drive will continue to select

the

track

while

you adjust the alignment. You

can

then

respecify track numbers,

continuing

this

procedure

until

the

tracks

on

the

alignment diskette

produce

the desired displays

on

the

oscilloscope. Be sure to read the

disk drive manufacturer's instructions and the alignment disk manufacturer's instruc-

tions before using this program.

To

use the Align option, enter A

and

press RETURN

when

the

TEST

menu

is displayed.

The

program will print:

Radial

head

alignment:

Check

your

manual

before

proceeding

ALIGNMENT

diskette

in

drive?

when

ready?

The

program will have substituted

the

hardware

number

of

the

drive you have

been

testing for

the

?

in

the

sample message given above.

Ii

.1

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