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1988-01-19
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T E S T D R I V E (tm)
A Comprehensive Disk Drive Diagnostic Tool
OPERATOR'S MANUAL
Version 1.2
Microsystems Development
4100 Moorpark Ave. #104
San Jose, CA 95117 USA
(408) 296-4000
Copyright (C) Microsystems Development 1987,1988.
All Rights Reserved
TEST DRIVE (tm) Version 1.2
TABLE OF CONTENTS
I. INTRODUCTION............................................1
II. WARRANTY................................................3
III. COPYRIGHT AND TRADEMARK INFORMATION.....................3
IV. ORDERING INFORMATION....................................4
V. BASIC DISK INFORMATION..................................5
VI. OPERATION...............................................7
F1 Program Information................................7
F2 General Test.......................................8
A) Sample display for a good drive.................9
B) Sample display for a bad drive.................10
F3 Alignment Test....................................11
A) Sample display for a good drive................13
B) Sample display for a bad drive.................14
F4 Spindle Speed.....................................15
A) Sample display for a good drive................16
B) Sample display for a bad drive.................16
F5 Write / Read Test.................................17
A) Sample display for a good drive................18
B) Sample display for a bad drive.................19
F6 Hysteresis Test...................................20
A) Sample display for a good drive................21
B) Sample display for a bad drive.................22
F7 Head Azimuth Test.................................23
A) Sample display for a good drive................24
B) Sample display for a bad drive.................25
F8 Hub Centering.....................................26
A) Sample display for a good drive................27
B) Sample display for a bad drive.................28
F9 Continuous Alignment..............................29
A) Sample display for a good drive................30
B) Sample display for a bad drive.................31
F10 Cleaning Utility..................................32
GLOSSARY OF TERMS...........................................34
CUSTOMER FEEDBACK FORM......................................37
Copyright (C) Microsystems Development 1987, 1988. i
TEST DRIVE (tm) Version 1.2
I. INTRODUCTION
Floppy disk drives are your computer's lifeline. They
provide the easiest and in many cases the only method of
transferring data from one computer to another. It is extremely
important that your computer's disk drives be operating at peak
performance at all times.
TEST DRIVE is a comprehensive floppy disk drive diagnostic
tool. It accurately measures and displays important operating
parameters, so that the exact operating condition of a drive can
be determined. In addition, this manual will help in
understanding the basics of disk operation, will help to analyze
the test results, and recommend corrective procedures.
Have you ever gotten the dreaded "Abort, Retry, Ignore?"
message when using a disk you thought was good? TEST DRIVE will
let you know if your drive is functioning properly.
Have you ever had problems in transferring files on disk
between different computers? Perhaps one computer can reliably
read and write to a diskette, but that same diskette will not
work in another computer? TEST DRIVE will pinpoint the problem.
Have you ever experienced unexplainable data loss on
diskettes? Perhaps a backup disk that your computer generated
months ago will no longer work in your computer? Periodic
testing with TEST DRIVE will help avoid this problem.
Do you need to be absolutely sure that the diskettes your
disk drive writes to can be read by another computer? TEST DRIVE
will confirm proper operation of your drive.
Have you ever had repairs made only to have the same or new
problems occur? TEST DRIVE will keep the technician honest by
reporting and quantifying the drive's performance, before and
after repair.
Want to dig in and make adjustments yourself? TEST DRIVE
provides continuous tests which can be run on your computer while
adjustments are made.
Ever wonder if you should be cleaning your drives, and if
so, how often? TEST DRIVE will indicate when cleaning may be
necessary. In addition, TEST DRIVE provides a helpful utility to
be used with a standard cleaning disk.
Does cleaning really help? TEST DRIVE can measure your
drive's performance before and after cleaning to determine if the
cleaning has been helpful.
How important is the diskette media? Bulk purchased generic
disks are generally tested to a lesser extent that the more
expensive name brands. In general, the generics are tested for
Copyright (C) Microsystems Development 1987, 1988. 1
TEST DRIVE (tm) Version 1.2
media defects only where a perfectly aligned drive would read and
write. If your drive's alignment is off, the probability of a
data loss using an inferior disk is greatly increased.
In addition, as drive densities continue to increase, data
is packed closer and closer together on the magnetic media. This
makes precise operation of your drive even more crucial.
The TEST DRIVE disk drive diagnostic package consists of the
TEST DRIVE program disk and an Dysan Digital Diagnostic Disk
(DDD). The program diskette contains the following files:
testdriv.com - Executable program
testdriv.doc - This documentation
To use the full capabilities of TEST DRIVE you will need the
Dysan precision alignment disk manufactured by Xidex Corporation,
available for sale from Microsystems Development (see ordering
information). The Dysan Digital Diagnostic Disk (DDD) is a test
disk with data written at precise distances and angles along the
tracks. TEST DRIVE will analyze the disk drive's ability to read
the specialized data patterns contained on the DDD. Some of TEST
DRIVE's tests require the use of the DDD, some do not.
Together, these two disks allow you, the user, to perform
comprehensive diagnostic tests, and perform certain adjustments
on floppy disk drives. The use of expensive and special test
equipment, oscilloscopes, etc., is unnecessary. The following
tests are performed by TEST DRIVE:
* General Test
* Alignment Test
Spindle Speed
Write/Read Test
* Hysteresis Test
* Head Azimuth Test
* Hub Centering
* Continuous Alignment * These tests require the
Cleaning Utility Dysan diagnostic disk
This version of TEST DRIVE will test 5 1/4" (360KB or less)
disk drives. Updates for high density 5 1/4" and 3 1/2" drives
are under development. Please inquire for availability.
System Requirements:
IBM PC/XT/AT or Compatible
64K RAM
DOS 2.0 or greater
An 80 column monitor (Color or Monochrome)
One working 5 1/4" disk drive that can load the program.
Once loaded, TEST DRIVE can later be run from a hard disk.
In fact, this is recommended for periodic testing to insure your
drives are in proper operating condition.
Copyright (C) Microsystems Development 1987, 1988. 2
TEST DRIVE (tm) Version 1.2
II. WARRANTY
Microsystems Development makes no warranty of any kind,
express or implied, including without limitation, any warranties
of merchantability and/or fitness for any specific application or
use. Microsystems Development shall not be liable for ANY loss
or damage arising from a failure of this program to operate in
the manner described, or in a manner desired by the user.
Microsystems Development shall not be liable for any damage to
data or property which may be caused directly or indirectly by
use of the program.
IN NO EVENT SHALL MICROSYSTEMS DEVELOPMENT OR IT'S SUPPLIERS
BE LIABLE FOR ANY CONSEQUENTIAL, INCIDENTAL OR EXEMPLARY DAMAGES
INCLUDING, BUT NOT LIMITED TO LOSS OF PROFITS OR REVENUES, LOSS
OF USE OF ANY PRODUCT, SERVICE OR REPLACEMENT COSTS, OR CLAIMS BY
ANY THIRD PARTY.
III. COPYRIGHT AND TRADEMARK INFORMATION
This version of TEST DRIVE may be copied and distributed
freely, with the following restrictions:
1) The program and documentation may not be modified,
2) The entire documentation file must be included with the
program,
3) No fee for the program may be charged outside of a
reasonable and customary charge for diskette media,
copying and/or shipping, and
4) It may not be packaged or sold in conjuction with any
other product.
The software code and screen displays used in TEST DRIVE are
the sole property of Microsystems Development, and may not be
copied, in any form, in whole or in part, or included in any
other program or document without the express written permission
of Microsystems Development.
If you'd like to make use of the full capabilities of TEST
DRIVE, you are encouraged to purchase the Dysan Diagnostic Disk
directly from us (see ordering information). This will help
support our effort, make you a registered user, and ensure that
you are kept up to date on new versions and enhancements.
Digital Diagnostic Diskette (DDD) is a trademark of Dysan.
Dysan is a registered trademark of Xidex Corporation.
IBM, IBM PC, IBM XT and IBM AT are registered trademarks of
International Business Machines Corporation.
MS-DOS is a trademark of Microsoft Corporation.
TEST DRIVE is a trademark of Microsystems Development.
Copyright (C) Microsystems Development 1987, 1988. 3
TEST DRIVE (tm) Version 1.2
IV. ORDERING INFORMATION
TEST DRIVE ORDER FORM
____ Dysan Digital Diagnostic Disk,
includes TEST DRIVE registration.......US$50.00 ea _______
____ Dysan disk, Latest version of TEST DRIVE,
Printed manual, and Registration........US$75.00 ea _______
Subtotal..............._______
Calif. residents add 6%, 6.5% or 7% sales tax........_______
Shipping charges. $2.50 within the continental
USA, $5.00 outside the continental USA..............._______
TOTAL...............$_________
______ Enclosed is a check for the above amount.
______ Please charge the above amount to my: Visa( ) MC( )
Account number:__________________________________Exp._____
Cardholder signature:_____________________________________
Purchase orders are accepted from qualified corporations.
Please call first for approval.
Name: _____________________________________________
Company: _____________________________________________
Address: _____________________________________________
_____________________________________________
Phone: (________) __________________________________
Remit to: Microsystems Development
4100 Moorpark Ave. #104
San Jose, CA 95117 USA
Phone: (408) 296-4000 10 AM to 4 PM Pacific Time.
Please inquire for availability of high density
5 1/4" and 3 1/2" versions of TEST DRIVE.
Copyright (C) Microsystems Development 1987, 1988. 4
TEST DRIVE (tm) Version 1.2
V. BASIC DISK INFORMATION
It is not necessary to have a degree in computer engineering
to use or benefit from TEST DRIVE. However, a basic
understanding of disk operation is helpful in identifying
problems. This section is meant to introduce you to basic disk
operation and terminology.
Diskette density specifies the amount of data the disk is
capable of holding. Densities are measured in kilobytes (KB) or
megabytes (MB). A kilobyte is 1024 bytes and a megabyte is 1000
kilobytes.
Information is written on a floppy disk magnetically, in
much the same way as audio information is stored on cassettes or
reel to reel tapes. The disk is rotating so data is written in
circles around the disk. These circles are called tracks. Each
track is divided into a number of sectors.
Each sector contains addressing marks, a fixed amount of
data, and a Cyclic Redundancy Check (CRC) for the data. The CRC
is an integrity check on the data. To retrieve data, the disk
drive controller must position the head over the desired track
and wait for the correct sector address to come around. Once the
sector is found, the disk controller reads the information from
the sector and stores it in a buffer. Then the CRC is computed
and compared to the CRC read from the disk. If this does not
compare an error is reported. A write operation occurs in much
the same manner except that the CRC is computed and stored with
the data and no verification is performed.
One indicator of disk density is the TPI specification.
This stands for Tracks Per Inch. In a 48TPI disk the tracks are
spaced 1/48 of an inch apart. Since a 360K diskette has 40
tracks, the width of the media containing data is somewhat less
than an inch. A 96 TPI diskette usually contains 80 tracks or
double the 40 tracks of a 360K. This would tend to make us
think that the density would be 720K, and this is true for the 3
1/2 inch technology. But the high density 5 1/4 inch standard
has 15 sectors per track instead of the 9 on a 360 KB disk. This
makes 1.2 MB (see table below). It seems that as the technology
becomes available to store more information on a disk, someone
will. However, the basics for data storage and retrieval is
relative constant no matter what the density is.
Copyright (C) Microsystems Development 1987, 1988. 5
TEST DRIVE (tm) Version 1.2
A 360KB diskette is formatted with 40 tracks, 9 sectors per
track, on both sides. 512 bytes are written in each sector.
Total 40 tracks 9 sectors 2 sides 512 bytes
bytes = ------ X ------- X X ------
side track sector
OR
Total bytes = 368,640
This is usually abbreviated to 360 KB, which is 360 x 1024
bytes.
The computer's operating system normally uses a few sectors
for overhead such as label and directory information. This is
why there are slightly less than 368,640 usable bytes on a
formatted disk.
The address marks and CRC are stored between the data and
are not included in the formatted capacity of a disk.
The following table illustrates the storage specifications
for the most commonly used disk densities:
Storage Physical Sectors Bytes Tracks Number
Size Size per Track per Sector per Side of Sides
----------------------------------------------------------------
160 KB 5 1/4" 8 512 40 1
180 KB 5 1/4" 9 512 40 1
320 KB 5 1/4" 8 512 40 2
360 KB 5 1/4" 9 512 40 2
1.2 MB 5 1/4" 15 512 80 2
720 KB 3 1/2" 9 512 80 2
1.44 MB 3 1/2" 18 512 80 2
This version of TEST DRIVE is designed to test 360 KB
drives. It will also test the first 3 types, however. Since the
first 2 types (160 and 180 KB) have only 1 head in the disk
drive, TEST DRIVE will report errors for Head 1, but the Head 0
results are correct.
Copyright (C) Microsystems Development 1987, 1988. 6
TEST DRIVE (tm) Version 1.2
VI. OPERATION
To operate, first load the operating system, then type
'testdriv', followed by the enter key. After the opening screen
appears, press any key to proceed to the main menu. You will see
a list of available selections. The number of drive selections
you see is dependent on the number of drives available in your
system. To make a selection, press the key indicated to the left
of the selection, or highlight your choice by using the up and
down arrows, then press enter.
Some tests require the use of the Dysan DDD. The speed test
will work with any standard formatted diskette OR the DDD. The
Write/Read test will only work a normal diskette, not the DDD.
TEST DRIVE always checks for the type of diskette inserted.
Data is never written to the DDD.
F1 Program Information
This screen gives a very brief "on-line" description of TEST
DRIVE. This document is provided for more detailed information.
After the information screen, the user is given the option
of displaying an 'Instant Order Form'. If a printer is attached,
simply use the PrtSc (print screen) function of your computer to
print a copy of the order form.
Copyright (C) Microsystems Development 1987, 1988. 7
TEST DRIVE (tm) Version 1.2
F2 General Test
In this test, six areas of drive performance are displayed
and measured, with Pass / Fail results given for each.
The measured results are also displayed, along with the
criteria used for Pass / Fail determination. For more detailed
information on each of the tests, see the appropriate section
describing that particular test in detail.
The TEST DRIVE general test is a good overall test which
should usually be run first to determine if there are any
problem areas. You encouraged to read the rest of this document
for a detailed description of each test.
Display Information:
Alignment and Sensitivity are combined in the first part of
the test. Three tracks for each head are measured. The drive
will pass the test if it can read data written at least +/- 8
milli-inches from the track centerline. Some manufacturers
specify +/- 9 milli-inches as passing criteria.
The next part of the test measures the drive's ability to
precisely seek to a specified track from either direction. This
is called hysteresis. Only one track is used for this test. If
the hysteresis is less than or equal to 1.5, it passes.
Next, the spindle speed is measured. For a 360KB disk
drive, the speed must be between 295 and 305 RPM. Some
manufacturers specify a smaller range.
Hub centering is the next test. The alternate offset track
which has data written at +/- 8 milli-inches offset around the
track is used for this part of the test. No errors allowed for
the drive to pass.
The last test in the general test is Head Azimuth. If the
drive can read data placed on the disk at an angle of +/- 39
minutes of a degree from centerline, it is considered good.
The Pass / Fail criteria used in the General Test is in
accordance with generally accepted standards. However, different
manufacturers, equipment, testing labs, etc., may use different
criteria. The criteria used in TEST DRIVE are not meant to imply
absolute minimums or maximums, but were simply chosen to help
interpret the data. In all cases, the measured data is also
displayed for the user's own interpretation.
In addition, the measured data displayed for the General
Test, as well as the other tests may vary slightly each time they
are run. This is because the tests push the drive past its
normal operating points, and operation outside the normal ranges
may not be consistent.
Copyright (C) Microsystems Development 1987, 1988. 8
TEST DRIVE (tm) Version 1.2
A) Sample display for a good drive
TEST DRIVE
General Test
Criteria Test Result
-------- --------- --------
Alignment / Track 0 Head 0 +/- 8 +10 -10 Pass
Sensitivity Track 0 Head 1 +/- 8 +11 -10 Pass
Track 19 Head 0 +/- 8 +10 -10 Pass
Track 19 Head 1 +/- 8 +10 - 9 Pass
Track 39 Head 0 +/- 8 +12 -10 Pass
Track 39 Head 1 +/- 8 + 8 - 9 Pass
Hysteresis Track 19 Head 0 1.5 0.5 Pass
Spindle Speed . . . . . . . . 295 - 305 301 Pass
Hub Centering . . . . Head 0 0 Errors 0 Errors Pass
Head Azimuth . . . . Head 0 +/- 39' +42 -42 Pass
Head 1 +/- 39' +42 -42 Pass
Analysis:
The above drive has passed all the tests, and the drive
appears to be in good condition.
Alignment - the drive was able to read data 8 milli-inches
or greater from the track centerline.
Hysteresis - is less than 1.5.
Spindle Speed - is in the acceptable range at 301 RPM.
Hub Centering - no errors were detected.
Head Azimuth - both heads were able to read data angled at
39 minutes of a degree or greater.
Copyright (C) Microsystems Development 1987, 1988. 9
TEST DRIVE (tm) Version 1.2
B) Sample display for a bad drive
TEST DRIVE
General Test
Criteria Test Result
-------- --------- --------
Alignment / Track 0 Head 0 +/- 8 + 6 -12 Fail
Sensitivity Track 0 Head 1 +/- 8 +11 -10 Pass
Track 19 Head 0 +/- 8 + 7 -11 Fail
Track 19 Head 1 +/- 8 +11 - 9 Pass
Track 39 Head 0 +/- 8 + 6 -11 Fail
Track 39 Head 1 +/- 8 + 8 - 9 Pass
Hysteresis Track 19 Head 0 1.5 2.0 Fail
Spindle Speed . . . . . . . . 295 - 305 309 Fail
Hub Centering . . . . Head 0 0 Errors 2 Errors Fail
Head Azimuth . . . . Head 0 +/- 39' +42 -42 Pass
Head 1 +/- 39' +42 -21 Fail
Analysis:
In the above example, Head 0 is poorly aligned. It is
shifted slightly away from the spindle as indicated by the high
negative values and low positive values.
The above drive has also failed the hysteresis test
indicating a possible problem with the positioning mechanism.
The TEST DRIVE General Test indicates that the spindle
speed is too high. Hub centering has also failed indicating a
possible clamping problem. It was not able to read some of the
data written at 8 milli-inches from track center.
Head 1 is also rotated slightly in one direction. It cannot
read data written in a position greater than 21 minutes of a
degree from track centerline.
For all the above problem areas, each individual test should
be run in full to determine the extent of each problem.
Copyright (C) Microsystems Development 1987, 1988. 10
TEST DRIVE (tm) Version 1.2
F3 Alignment Test
Alignment is a measure of how centered the read/write head
is over the track center. This is sometimes called Radial
Alignment. For a 48TPI disk, each track is 1/48 inch wide which
is 20.833 milli-inches. Data on the progressive offset tracks of
the DDD are progressively displaced from 6 to 13 milli-inches
toward and away from the spindle. Therefore, data will span 26
milli-inches which is slightly wider than a 48 TPI track. The
tracks adjacent to the progressive offset track of the DDD are
not used.
Sensitivity is a measure of how much data on a given track
is readable, or the width to which the head is sensitive to. If
a head is able to read data from +10 to -10 milli-inches on a 20
milli-inch track, you have a drive performing very well. If the
same drive read +13 to -7, we still have perfect sensitivity but
the alignment is now shifted.
The successful reading of data greater than +/- 10 milli-
inches will cover the entire track. If a disk drive is able to
read data that is progressively offset to +8 and only to -7, the
drive is slightly mis-aligned and suffers from poor alignment
sensitivity. A drive that will read -11 to +8 milli-inches,
shows good sensitivity but is poorly aligned. In the latter
case, the drive will likely function reliably until the head
becomes dirty and the sensitivity decreases.
The alignment test will push the drive's operation beyond
normal limits and report back the results, You will certainly
see errors in this test simply because the drive is not supposed
to read data placed beyond the normal track width.
Display Information:
The alignment test uses all of the progressive offset tracks
available on the Dysan Digital Diagnostic test. These are tracks
0, 5, 16, 19, 30, and 39. It attempts to read all the data on
the tracks, from 6 to 13 milli-inches off center in either
direction. If the read was successful, it will display four
solid characters, represented in this document as '~~~~'. If the
read was not successful, it will display 'erxx', where xx is the
hex error code returned by the BIOS read routine.
Copyright (C) Microsystems Development 1987, 1988. 11
TEST DRIVE (tm) Version 1.2
The following is a list of errors than can be reported:
ERROR ERROR
CODE TYPE REASON
---- ------------------ ---------------------------------
er80 time_out Drive did not respond
er40 bad_seek Drive failed to seek to track
er20 bad_nec Drive controller chip failed
* er10 bad_crc Cyclic redundancy check failed
er09 dma_boundary Attempt to direct memory
across 640K boundary
er08 bad_dma DMA overrun on operation
er06 media_change media not identified
on multiple media drive
* er04 record_not_found sector not found
* er02 bad_addr_mark address mark not found
* Commonly induced errors in alignment test.
Adjustments for poor Alignment Sensitivity:
Poor alignment sensitivity indicates that the heads are not
picking up as much data as they should. This could be due in
part to a build up of dirt on the heads. The correction for this
to simply clean the heads. If the problem is a dirty head,
cleaning will eventually correct the problem. Cleaning, however,
generally will not have a drastic effect. If the problem
persists, it may be necessary to replace the drive since
replacing the head assembly usually is not done economically.
Adjustments for poor Alignment:
Most drives come equipped with an adjustment screw which
will translate a turning motion into a linear head adjustment.
Since drives are becoming so inexpensive however, manufacturers
are saving costs by eliminating expendable mechanisms such as
alignment hardware. It is more cost effective for the
manufacturer to set the alignment once, than it is to provide
adjustment screws.
If your drive has such an adjustment, we suggest you use the
Continuous Alignment Test if you wish to make adjustments.
Please see the explanation of that test for more information.
If the alignment is just slightly off, we recommend that you
leave it alone, and monitor its condition with TEST DRIVE.
Copyright (C) Microsystems Development 1987, 1988. 12
TEST DRIVE (tm) Version 1.2
A) Sample display for a good drive
TEST DRIVE Alignment Test
<------------------------ Track ------------------------->
39 30 19 16 5 0 0 5 16 19 30 39
- 13 er02 er02 er02 er02 er02 er02 er02 er02 er02 er04 er10 er04
- 12 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02
- 11 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02
- 10 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ er02 er02
- 9 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ er02
- 8 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
- 7 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
- 6 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
Head 0 Head 1
+ 6 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
+ 7 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
+ 8 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
+ 9 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
+ 10 er02 er02 er02 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ er02
+ 11 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02
+ 12 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02
+ 13 er02 er04 er04 er04 er04 er04 er04 er04 er02 er02 er04 er02
Analysis:
This drive is in good shape, the '~~~~' pattern is
symmetrical between the + and - readings. This indicates very
good alignment. This test also indicates the sensitivity of the
head. For the most part, the heads are sensitive to data from -
10 to +10 milli-inches or a total of 20 milli-inches. On track
39 of head 1, the head is sensitive only from -8 to +9 milli-
inches or 17 milli-inches. Since these tracks on the diskette
are 20 milli-inches wide, this drive is performing well.
Copyright (C) Microsystems Development 1987, 1988. 13
TEST DRIVE (tm) Version 1.2
C) Sample display for a bad drive
TEST DRIVE Alignment Test
<------------------------ Track ------------------------->
39 30 19 16 5 0 0 5 16 19 30 39
- 13 er02 er02 er02 er02 er02 er02 er02 er10 er04 er10 er10 er04
- 12 er02 er02 er02 er02 er02 er02 er02 er04 er04 er02 er02 er02
- 11 er02 er02 er02 er02 er02 er02 er02 er04 er02 er02 er02 er02
- 10 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02
- 9 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02
- 8 er02 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ er02 er02 er02 er02 er02
- 7 er02 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ er02 er02 er02 er02
- 6 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ er02 er02 er02
Head 0 Head 1
+ 6 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
+ 7 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
+ 8 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
+ 9 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
+ 10 er02 er02 er02 ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ~~~~
+ 11 er02 er02 er02 er02 er02 er02 er02 er02 er02 ~~~~ ~~~~ ~~~~
+ 12 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02 er02
+ 13 er02 er04 er04 er04 er04 er04 er04 er04 er02 er02 er04 er02
Analysis:
This drive shows problems in both alignment and possibly in
sensitivity as well. The alignment pattern shows a shift of the
successful read operations toward the positive side. This
indicates that the physical positioning of the head is shifted
off the center of the track. This problem could be remedied by
adjusting the head positioning to make the pattern symmetrical.
For most of the disk the total sensitivity reads about +10
to -7 or 17 milli-inches of read sensitivity. However, head 1
cannot even read data at -6 milli-inches on tracks 19, 30 and 39.
In this case, the sensitivity cannot be determined until the
alignment is corrected.
Copyright (C) Microsystems Development 1987, 1988. 14
TEST DRIVE (tm) Version 1.2
F4 Spindle Speed
This test measures the speed at which the diskette rotates
in the drive. It can use either the Dysan DDD or a standard
formatted diskette. If an error occurs when the test starts, the
user is given the opportunity to override by pressing 'O'. If
errors still occur, speed will be displayed as '---'.
Speed is measured by the time it takes for the diskette to
rotate from a given sector back around to the same sector. This
time is then converted to revolutions per minute, or RPM. The
acceptable range is 295 to 305 RPM. A drive can operate outside
this range and cause no apparent problems, but it should be
adjusted to be within range. Otherwise, it may be difficult to
interchange data written by it with another drive.
Other types of drives operate at different speeds as
follows:
high density 5 1/4" 355 to 365 RPM
3 1/2" 295 to 305 RPM
Display Information:
The test will run for several trials, continually updating
the speed and the pointer on the display. It then stops in order
to save wear on the disk. If you wish to run it continuously,
press "C". Any other key will return you to the main menu. If
you select "C" for continuous testing, the test will not stop
until you press another key.
Adjustment:
On most drives,there is a small screw adjustment for spindle
speed. This adjustment can be made while this test is running,
and TEST DRIVE will continually update the display accordingly.
If the speed is adjusted too far out of range so that the program
can no longer read any data, TEST DRIVE will report '---'.
If the speed varies erratically, say 4 RPM or more, the
problem could be a loose or bad drive belt. In many cases,
replacement of the belt will help or cure the problem.
Some drives have direct drive from the motor so do not have
belts. Some do not even have a speed adjustment. In these
cases, the drive should either be repaired professionally or
replaced.
Copyright (C) Microsystems Development 1987, 1988. 15
TEST DRIVE (tm) Version 1.2
A) Sample display for a good drive
TEST DRIVE Spindle Speed Measurement
|---- Acceptable ---|
| Range |
285 290 295 300 305 310 315
|---------|---------|---------|---------|---------|---------|
^
Speed = 300 RPM
Using Dysan DDD Model 508-400
Analysis:
Here, the speed is directly in the middle of the acceptable
range, at 300 revolutions per minute.
B) Sample display for a bad drive
TEST DRIVE Spindle Speed Measurement
|---- Acceptable ---|
| Range |
285 290 295 300 305 310 315
|---------|---------|---------|---------|---------|---------|
^
Speed = 291 RPM
Using Dysan DDD Model 508-400
Analysis:
The above drive is running slightly slow, at 291 revolutions
per minute.
Copyright (C) Microsystems Development 1987, 1988. 16
TEST DRIVE (tm) Version 1.2
F5 Write / Read Test
This test measures the drive's ability to correctly write,
then read back, each sector of the disk. It can also be used to
verify the operation of a particular diskette, that is, its
ability to store data on all parts of it.
The computer's operating system normally checks both the
write and the read processes for errors. TEST DRIVE checks for
those errors and reports them. In addition, each byte that was
written is compared with what was read back to determine if it's
exactly the same. Any discrepancy is reported as a compare
error.
Display Information:
This test requires the use of a formatted scratch diskette.
It writes 512 random bytes of data to each sector on the disk,
reads them back and compares them. Errors can occur while
Writing, Reading or Comparing the data, and are reported sector
by sector. There are several types of write and read errors
returned by the system's BIOS, such as bad seek or bad CRC.
These errors are not reported individually in this test. Only
'W' or 'R' are displayed, depending on whether the error was the
result of a write or a read operation.
Since TEST DRIVE writes random data to all sectors including
those used by the operating system for file and directory
information, any diskette used for this test will have to be re-
formatted before it can be used for normal purposes.
Insure that the media used is of high quality and does not
introduce errors into the test.
No errors should be tolerated for this test.
Adjustment:
There is no adjustment. In some cases, the drive heads may
simply need to be cleaned. Use a good quality cleaner and try
the test again.
Copyright (C) Microsystems Development 1987, 1988. 17
TEST DRIVE (tm) Version 1.2
A) Sample display for a good drive
TEST DRIVE Write / Read Test
Sector-+ Track -->
| 0 - - - 9 - - - 19 - - - 29 - - - 39
1 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-
2 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
~ = Sector OK 3 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
4 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
5 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Head
W = Write error 6 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| 0
7 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
R = Read error 8 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
9 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
C = Compare error 1 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-
2 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
3 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
Total errors = 0 4 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
5 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Head
6 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| 1
7 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
8 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
9 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-
Analysis:
The above display indicates that the program was able to
successfully write, then read back the same data, to every sector
on the diskette.
Copyright (C) Microsystems Development 1987, 1988. 18
TEST DRIVE (tm) Version 1.2
B) Sample display for a bad drive
TEST DRIVE Write / Read Test
Sector-+ Track -->
| 0 - - - 9 - - - 19 - - - 29 - - - 39
1 - ~~C~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-
2 - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
~ = Sector OK 3 - W~~~~~~~~~~~~~~~W~~~~~~~~~~~~~~~~~~~~~~~|
4 - WR~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
5 - WR~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Head
W = Write error 6 - WW~~~~~~~~~~~~~~~W~~~~~~~~~~~~~~~~~~~~~~| 0
7 - WR~~~~~~~~~~~~~~~R~~~~~~~~~~~~~~~~~~~~~~|
R = Read error 8 - R~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
9 - ~~~~~~~~~~~~~~~~~~~~~~~~R~~~~~~~~~~~~~~~|
C = Compare error 1 - ~~~~~C~~~~~~~~~~~~~~~~~~WR~~~~~~~~~~~~~~-
2 - ~~~WRW~~~~~~~~~~~~~~~~~~WWR~~~~~~~~~~~~~|
3 - ~~~WWWW~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
Total errors = 54 4 - ~~~WWWW~~~~~~~~~~~WWW~~~~~~~~~~~~~~~~~~~|
5 - ~~~WWRW~~~~~~~~~~~WWW~~~~~~~~~~~~~~~~~~~| Head
6 - ~~~~RWW~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| 1
7 - ~~~~WRR~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
8 - ~~~~~RR~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
9 - ~~~~~RRWC~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-
Analysis:
The above display shows many errors of different types. The
problem could simply be a bad diskette. If the problem occurs
with more than 1 formatted diskette of good quality, there is a
problem with the read/write mechanism of the drive.
Copyright (C) Microsystems Development 1987, 1988. 19
TEST DRIVE (tm) Version 1.2
F6 Hysteresis Test
Hysteresis is a measure of the drive mechanism's ability to
seek a specified track from either direction and position the
head in precisely the same position.
The head is moved to an inner track (toward the hub) and
then sent to the middle of the disk. Measurements of alignment
are recorded and displayed. The head is then sent to an outer
track and subsequently sent to the center again. Measurements
are taken and compared to the previous center measurements to
determine the hysteresis.
The hysteresis error is determined by the difference in the
center of the alignment pattern. For example: The first
alignment readings are +10 and -9 milli-inches. This is to say
that the head is in such a position that data offset +10 and -9
milli-inches can be read. The head is then sent to the outer
track and back to the center to again take readings of +10 and -9
milli-inches. This is simply 0 milli-inches of hysteresis. The
head had positioned itself at precisely the same position when
seeking a track from either direction. If the second set of
readings were +9 and -10 the hysteresis would be 1.0 milli-inch.
In general, the center of each reading is compared to determine
the hysteresis. The center of +10 and -9 is +0.5 and the center
of +9 and -10 is -0.5. The difference is 1 milli-inch.
Although these numbers are confusing the graphical
representation will make more sense.
In this test, the alignment sensitivity is ignored and only
the center of the data pattern is used in determining hysteresis.
The actual alignment of the drive is unimportant in this test but
the repeatability of the positioning is crucial. Disk drives
with excessive hysteresis are unreliable.
Display Information:
TEST DRIVE uses two of the middle progressive offset tracks
on the DDD for this test: tracks 16 and 19. The horizontal bars
on the display span the distance from track centerline that the
drive was able to read successfully. Each set of bars is for a
particular head and track, with the head having been positioned
there from opposite directions. Ideally, each set of bars should
be equal in length.
Adjustment:
There is no adjustment and the drive should be discarded or
sent to the manufacturer for reconditioning.
Copyright (C) Microsystems Development 1987, 1988. 20
TEST DRIVE (tm) Version 1.2
A) Sample display of a good drive
TEST DRIVE Hysteresis Test
<----------- m i l l i - i n c h e s ---------->
H Tr Dir Error -13-12-11-10 -9 -8 -7 -6 +6 +7 +8 +9+10+11+12+13
- -- --- ----- |--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
0 16 --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<-- 0.0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 16 --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<-- 0.5 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0 19 --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<-- 0.5 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 19 --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<-- 0.0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Analysis:
The above drive has no significant hysteresis. Some error
is normal since data written too far off track center may be
read unreliably. If the error is consistently greater, the drive
has a problem.
The drive also exhibits good sensitivity since it can read to
a minimum of +10 and -9 milli-inches.
Copyright (C) Microsystems Development 1987, 1988. 21
TEST DRIVE (tm) Version 1.2
B) Sample display of a bad drive
TEST DRIVE Hysteresis Test
<----------- m i l l i - i n c h e s ---------->
H Tr Dir Error -13-12-11-10 -9 -8 -7 -6 +6 +7 +8 +9+10+11+12+13
- -- --- ----- |--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
0 16 --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<-- 2.0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 16 --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<-- 2.0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0 19 --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<-- 1.5 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 19 --> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<-- 2.5 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Analysis:
This drive has more hysteresis than normal and indicates a
possible problem with its positioning mechanism.
For example, when head 1 is moved toward the spindle to
track 19 it can read data at 8 milli-inches away from the spindle
and 12 milli-inches toward the spindle. When head 1 is moved
away from the spindle and is stopped at track 19, it can read
data at 12 milli-inches away from the spindle and 9 inches toward
the spindle. This indicates that the head was not in the same
physical location.
This drive would probably pass the alignment test however,
since in all the above cases it can read data to +/-8 milli-inches.
Copyright (C) Microsystems Development 1987, 1988. 22
TEST DRIVE (tm) Version 1.2
F7 Head Azimuth Test
Head rotation or azimuth is an indication of the angular
position of the head with respect to a line tangent to the track
centerline. If the head is "twisted", or "rotated", with respect
to the track centerline the data written to the diskette will be
"slanted" and will eventually cause problems when interchanging
diskettes with other drives.
For these measurements, TEST DRIVE uses the azimuth rotation
track (track 34) of the DDD. This track has data written on
track centerline, but at increasingly greater angles, both toward
and away from the spindle. The angle range from 21 to 42 minutes
of a degree. If the drive's head is angled slightly out of
position, it will be able to read data on the tracks at one
angle, but will have problems with data written at the opposite
angles.
Display information:
For each successful read operation, the display shows four
slashes '/' or four reverse slashes '\'. It will show four
capital x's if it was unable to read data written at a particular
angle.
Adjustment:
There is no adjustment for head azimuth in most drives, and
the head assembly or the entire drive should be replaced.
Copyright (C) Microsystems Development 1987, 1988. 23
TEST DRIVE (tm) Version 1.2
A) Sample display of a good drive
TEST DRIVE Head Azimuth Test
/
\ / /
\ \ / / /
\ \ \ / / / /
\ \ \ \ / / / /
\ \ \ \ / / / / /
X \ \ \ \ / / / / / /
X \ \ \ \ \ / / / / / / /
X \ \ \ \ \ Head / / / / / / /
X \ \ \ \ \ 1 / / / / / /
\ \ \ \ \ / / / / /
\ \ \ \ / / / /
\ = OK \ \ \ \ / / / /
\ \ \ Head / / /
X = Error \ \ 0 / /
\ /
-42 -39 -36 -33 -30 -27 -24 -21 +21 +24 +27 +30 +33 +36 +39 +42
<--------------------- Angular Rotation ---------------------->
Angular position of head in minutes of a degree.
Analysis:
The above drive shows no problems with head azimuth. Both
heads were able to acceptably read the data on the test tracks.
Copyright (C) Microsystems Development 1987, 1988. 24
TEST DRIVE (tm) Version 1.2
B) Sample display of a bad drive
TEST DRIVE Head Azimuth Test
\ /
\ \ / /
\ \ \ / / /
\ \ \ \ / / / /
\ \ \ \ / / / /
\ \ \ \ \ / / / / X
\ \ \ \ \ \ / / / / X X
\ \ \ \ \ \ \ / / / / X X X
\ \ \ \ \ \ \ Head / / / X X X X
\ \ \ \ \ \ 1 / / X X X X
\ \ \ \ \ / X X X X
\ \ \ \ / X X X
\ = OK \ \ \ \ / / X X
\ \ \ Head / / X
X = Error \ \ 0 / /
\ /
-42 -39 -36 -33 -30 -27 -24 -21 +21 +24 +27 +30 +33 +36 +39 +42
<--------------------- Angular Rotation ---------------------->
Angular position of head in minutes of a degree.
Analysis:
The above display indicates that Head 1 does not have an
azimuth problem, but that Head 0 may be rotated slightly in one
direction, Head 0 was able to read all the data angled in one
direction, but could not read data angled at 27' or greater in
the opposite direction.
Copyright (C) Microsystems Development 1987, 1988. 25
TEST DRIVE (tm) Version 1.2
F8 Hub Centering
Hub Centering is a measure of how well the disk clamping
mechanism holds the disk media centered and rotates it in a
perfect circle.
The DDD has three test tracks for three levels of clamping
sensitivity, 7, 8 and 9 milli-inches. These tracks are called
the alternate offset tracks. Data is alternately offset +/- 7,
+/- 8 or +/- 9 milli-inches all around the disk. All disks
should pass the 7 milli-inch test and some with perfect clamping
and good sensitivity will pass the 9 milli-inch test. A drive
should be considered to be in good shape if the 8 milli-inch test
is passed.
Display information:
The display for hub centering shows 3 sinusoidal waveforms
each indicating results from different tracks. A solid block
(indicated by a '~' in this document) is displayed for a
successful read, and an 'X' is displayed for an unsuccessful
read.
The results for head 0 are displayed first, and the user is
given the option to test head 1 also.
Adjustment:
There generally is no adjustment for disk clamping or hub
centering. Poor centering us usually an indication of a worn
out drive.
Note: The DDD does not have a reinforcing hub. This is to
avoid any centering error that could be introduced by
the hub reinforcer ring.
Copyright (C) Microsystems Development 1987, 1988. 26
TEST DRIVE (tm) Version 1.2
A) Sample of a good drive
TEST DRIVE Hub Centering Head 0
~ ~
~ ~
~
~ ~ ~
~ ~ X
~ ~
9 --> ~ ~ ~ ~
~ ~ ~ ~
~ ~ ~
8 --> ~ ~ ~
~ ~ ~ ~
~ ~ ~ ~
7 --> ~ ~
~ ~ ~
~ ~ ~
~
~ = OK X = Error ~ ~
~ ~
<----------------- One Disk Revolution ------------------->
Analysis:
This drive is functioning properly. The 9 milli-inch test
shows an occasional error but this is acceptable.
Copyright (C) Microsystems Development 1987, 1988. 27
TEST DRIVE (tm) Version 1.2
B) Sample of a bad drive
TEST DRIVE Hub Centering Head 0
~ X
X ~
X
~ ~ X
X ~ ~
X ~
9 --> X ~ ~ ~
X ~ ~ X
~ X ~
8 --> X ~ ~
~ X X ~
~ X X ~
7 --> ~ ~
~ X ~
~ ~ ~
~
~ = OK X = Error ~ ~
~ ~
<----------------- One Disk Revolution ------------------->
Analysis:
The drive is not rotating the disk in a perfect circular
fashion. Errors may be tolerated at 9 milli-inches but never at
7 milli-inches. This indicates that as the disk is rotating,
with the head in a fixed position, the data track is not
consistently under the head.
Copyright (C) Microsystems Development 1987, 1988. 28
TEST DRIVE (tm) Version 1.2
F9 Continuous Alignment
The continuous alignment test is provided as a way to `zero
in' on a particular head and track and take continuous
measurements.
The test defaults to head 0, track 19, but by using the
left, right, up and down arrows, the user can select any of the
progressive offset tracks on the DDD.
When the continuous alignment test begins to run, it will
first test for the presence of the Dysan DDD. If it is present,
the test will proceed. If it is not, the operator is given the
opportunity to override and continue anyway. If the drive is so
poorly adjusted that TEST DRIVE cannot sense the Dysan disk, the
override feature allows the operator to at least start the test,
presumably so that a technician can attempt adjustment. If the
user selects the override feature, and a non-Dysan DDD is
inserted, TEST DRIVE will report "Unable to read any data on
disk" for each measurement trial.
Display information:
The horizontal bars on the display span the distance from
track centerline that the drive was able to read. When new
measurements are taken, the previous bars are scrolled down, and
the current measurements are displayed on the top line. If the
head or track is switched, all previous measurements are cleared
before new data is displayed.
Adjustments:
If you attempt to make alignment adjustments, you can do so
while the continuous alignment test is running. The test will
continually report any change. Keep in mind that a disk drive is
a precision instrument. If the data pattern shows a 2 milli-inch
shift, this is indicating the physical positioning needs to be
shifted 1/1000 of an inch to gain symmetry. This is a very small
distance. Once you start to move the head assembly, the
alignment may worsen.
In any case, when adjusting the heads be careful not to
cause damage to the DDD.
Copyright (C) Microsystems Development 1987, 1988. 29
TEST DRIVE (tm) Version 1.2
A) Sample display of a good drive
TEST DRIVE Continuous Alignment Test
<----------- m i l l i - i n c h e s ---------->
-13-12-11-10 -9 -8 -7 -6 +6 +7 +8 +9+10+11+12+13
|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
Current > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Previous ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Use the up & down arrows > Head 0 Track 19 < Use the left & right
to switch heads arrows to switch tracks
Analysis:
The above drive appears to be perfectly aligned, as
evidenced by the fact that it can read data at equal distances on
either side of track center. If other tracks and the other head
also display good results, alignment can be considered excellent.
Sensitivity is 20 (10 + 10) which is also very good.
Keep in mind, that some variations in the above display are
normal, particularly at the sides. Data written greater than 8
milli-inches from track center may be read unreliably. If this
test display were to show some slight variation in alignment or
sensitivity, it does not necessarily mean that the drive is in
need of adjustment.
Some variation is normal since data written too far off
track center may be read unreliably.
Copyright (C) Microsystems Development 1987, 1988. 30
TEST DRIVE (tm) Version 1.2
B) Sample display of a bad drive
TEST DRIVE Continuous Alignment Test
<----------- m i l l i - i n c h e s ---------->
-13-12-11-10 -9 -8 -7 -6 +6 +7 +8 +9+10+11+12+13
|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|--|
Current > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Previous ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Use the up & down arrows > Head 0 Track 19 < Use the left & right
to switch heads arrows to switch tracks
Analysis:
The above drive shows poor alignment since the horizontal
bars are all skewed to one side. It is definitely in need of
adjustment.
The head is shifted slightly away from the spindle as
indicated by the higher negative values. Sensitivity is 19 (6 +
13 or 7 + 12), which is good. Therefore, this drive can probably
be adjusted to within acceptable tolerances.
Copyright (C) Microsystems Development 1987, 1988. 31
TEST DRIVE (tm) Version 1.2
F10 Cleaning Utility
The disk read/write heads may in time build up a deposit of
oxide, smoke or dust particles that will adversely effect the
sensitivity of the heads. Depending on the amount of buildup,
cleaning may improve the performance of the disk drive.
The TEST DRIVE cleaning utility is designed to be used with
a standard cleaning disk and cleaning solution. It will rotate
the disk for a set length of time, and move the heads across the
surface of the cleaning disk.
Most manufacturers of cleaning disks recommend that you
invoke a DIR command and continue the drive motion for about 30
seconds. This will cause the head to seek to track zero looking
for the directory information. In doing this, the only portion
of the cleaning disk that is used is the portion physically
located where track zero is supposed to be (the outer edge). The
TEST DRIVE cleaning utility will move the head across the disk
from track 0 to track 39. Each cycle from track 0 to 39 takes
approximately 10 seconds. By using the cleaning utility in
conjunction with a standard cleaning disk you will get more
efficient usage of the cleaning disk and more efficient cleaning
of the heads.
Most drive cleaners recommend that you use the cleaning disk
only 10 to 20 times before discarding. Since the head itself is
physically less that 1/8 inch wide, and it can be moved almost 1
inch across the disk, it stands to reason that if the head
positioning is varied and you follow manufacturers advice, you
can expect to obtain 80 or more cleanings from a single cleaning
disk.
Drive cleaning tips:
Does cleaning really help? We recommend that you monitor
head sensitivity with TEST DRIVE before and after you clean the
heads to illustrate what effect the cleaning has on the
performance of the heads. Sensitivity is a measure of how well
the heads read. The General Test and the Alignment Test indicate
sensitivity in the +x to -x readings. The larger the span
between the + and - numbers the greater the sensitivity. Take
note of the sensitivity before cleaning and after. If the
sensitivity did not increase the heads didn't need cleaning.
Are cleaning disks harmful to the drives? The cleaning
media in the revolving disk cleaners must be stiff to allow for
the hub to clamp and spin it. This stiff characteristic
generally means that the cleaner is somewhat abrasive also.
Excessive usage of abrasive cleaning disks may cause excessive
wear on the heads, but occassional cleaning is not harmful.
Copyright (C) Microsystems Development 1987, 1988. 32
TEST DRIVE (tm) Version 1.2
How often should floppy disk drives be cleaned? One
cleaning disk manufacturer recommends daily cleaning, most all
recommend cleaning at least once a week. However, we recommend
that you clean your drive only when needed based on usage and
environment. If the environment is smoky or dusty the heads will
build up a deposit quickly. In an extremely clean location the
heads will require less cleaning. The amount of usage the drive
receives will only slightly effect the cleaning requirements.
Since the time the head is in contact with the media is generally
so short, this does not have as much effect as the environment.
In a generally clean environment with moderate usage a disk drive
may require cleaning every 3 to 4 months, but there are no hard
and fast rules. The best indicator of when to clean your drives
can be obtained by using TEST DRIVE to periodically check their
performance.
What is the best way to clean disk drives? Any standard
cleaning disk is acceptable. It appears as though there are only
a few manufacturers that provide several name brand distributors.
We recommend that a lint free cloth saturated in a good cleaning
solvent be used if access to the head assembly if possible. If
the access is limited be careful not to disturb the alignment by
moving the head assembly. The commercially available cleaning
solution provided with cleaning disks is generally a form of
isopropyl alcohol and freon. This is fine to use but isopropyl
alcohol by itself is sufficient to do the job. The purer it is,
the better. Ninety-one percent isopropyl alcohol is available in
many drug stores, and 99% is rarer but still available.
Copyright (C) Microsystems Development 1987, 1988. 33
TEST DRIVE (tm) Version 1.2
GLOSSARY OF TERMS
1.2MB 1200 x 1024 or 1,228,800 bytes. The amount of
data stored on a high density diskette, High
density drives are normally found in AT type
computers.
360KB 360 * 1024 or 368,640 bytes. The amount of data
stored on standard 5 1/4 inch diskette.
720KB 720 * 1024 or 737,280 bytes. The amount of data
stored on a 3 1/2 inch diskette.
Alignment The measure of how centered the Read/Write head is
over the track centerline. Sometimes referred to
as Radial Alignment.
Alignment The measure of how much of the track the head will
Sensitivity respond to. In a 48 TPI drive, if the head reads
-11 to +10 milli-inches the head is sensitive to
21 milli-inches of data and is very good. If the
head reads -8 to +7 milli-inches of data the
sensitivity is 15 milli-inches and is poor.
Alternate Alternate offset refers to the data pattern on the
Offset centering test tracks. There are 3 tracks used
for this test. Data is written at +/- 7 milli-
inches on the first, +/- 8 on the second, and
+/- 9 on the third.
Azimuth The angular displacement of the Read/Write Head
relative to a line tangent to the track center
line.
BIOS Basic Input/Output System. The built functions of
a computer to facilitate many functions including
disk reads and writes.
Centering The ability of the disk clamping mechanisms to
clamp on the diskette precisely in the center of
the disk and spin the disk in a perfect circle.
See Alternate Offset. Sometimes referred to as
eccentricity.
Clamping See Centering.
CRC Cyclic Redundancy Check. A type of error checking
used by the computer's BIOS to help insure
integrity of data on a diskette.
Cylinder A set of concentric equal size tracks, stacked on
top of one another. Usually used when discussing
hard disks, but sometimes with diskettes also.
Copyright (C) Microsystems Development 1987, 1988. 34
TEST DRIVE (tm) Version 1.2
Diskette The magnetic media inserted into a floppy disk
drive, used to store information.
DDD Digital Diagnostic Disk, manufactured by Dysan
Corporation. Contains data patterns written at
precise angles and distances from track center.
Eccentricity See Centering.
Head The portion of the drive that reads and writes the
stored magnetic information from the diskette.
Hub The center of the diskette sometimes reinforced
with ring.
Hysteresis A measure of the drive mechanism's ability to seek
to a specified track from either direction and
position the head at precisely the same distance
from the center.
Milli-inch One 1/1000th of an inch.
Minute One 1/60th of a degree. Used to measure the
rotational position or azimuth of a head relative
to track centerline.
Progressive Progressive offset refers to the data pattern on
Offset the alignment test tracks. The pattern starts at
-/+6 milli-inches and progresses to -/+13 milli-
inches. The data progressively gets farther away
from track center.
Radial See Alignment
Alignment
RPM Revolutions per minute, the number of times the
disk spins around in 1 minute.
Sector A slice of a track containing data, like a piece
of a pie. Each track contains a number of
sectors. For 360KB drives, there are 9 sectors
per track. High density 1.2MB drives use 15
sectors per track.
Seek The process of moving the drive's head to a
particular track.
Sensitivity See Alignment Sensitivity
Spindle The mechanism in the disk drive used to spin the
diskette.
Copyright (C) Microsystems Development 1987, 1988. 35
TEST DRIVE (tm) Version 1.2
Spindle Speed The angular rotational speed of the diskette
media, or how fast the disk spins around. This is
measured in revolutions per minute (rpm).
TPI Tracks per inch. The density of tracks on a disk.
For example: A 48 TPI disk will have 48 tracks
per inch, each track spaced 1/48 of an inch apart.
A disk with 40 tracks will utilize 40/48ths of an
inch on the disk.
Track A circle around a disk made up of a number of
sectors. Sometimes called a cylinder.
Copyright (C) Microsystems Development 1987, 1988. 36
TEST DRIVE (tm) Version 1.2
CUSTOMER FEEDBACK FORM
Your comments, suggestions, criticisms, etc. are most welcome.
They help us bring you a quality product at a reasonable price.
Just fill out this form and send it to us.
Brand and model of computer:_____________________________________
Comment( ) Suggestion( ) Criticism( ) Problem( ) Other___________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Name: ________________________________________________
Company: ________________________________________________
Address: ________________________________________________
City, State, Zip: _______________________________________
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Do you need a reply?_________ Are you a registered user?_________
We guarantee a reply to all registered users who request one.
Microsystems Development may use the information you supply
without incurring any obligation whatsoever.
Mail this form to: Microsystems Development
4100 Moorpark Ave. #104
San Jose, CA 95117 USA
Copyright (C) Microsystems Development 1987, 1988. 37
