-TRACKER V4.1 Copyright (C) 1990 Wesley J. Wiese. Documentation for Digital Track Display.
HTracker V4.1 DTD
LEGAL NOTICES
All documents in this
@ TRACKER V4.1
series are Copyright (C) 1989,1990 Wesley J. Wiese, Wes 'n' Les Electronics. All rights reserved. Any and all consequences resulting from the use of these documents is the expressed responsibility of the user.The author will not be held liable and does not imply any warranty or guarantee. The author does certify that all information presented in these documents was correct, to his knowledge, at the time of distribution of these documents.
All documents in this
@ TRACKER V4.1
series are the sole property of the author, who retains all copyrights and patents to the material presented.
All documents in this
@TRACKER V4.1
series will not be distributed or reproduced or stored in any retrieval system in whole or part form without the prior permission of the author.
HARDWARE KNOCKS - DIGITAL TRACK DISPLAY
@Copyright (C)April 26,1989 By Wesley J. Wiese
All Rights Reserved
HTRACKER V4.1
This document appeared fir fir
HARDWARE KNOCKS - DIGITAL TRACK DISPLAY
@Copyright (C)April 26,1989 By Wesley J. Wiese
All Rights Reserved
HTRACKER V4.1
This document appeared first in the Southern Maine Commodore User's Group (
@S.M.C.U.G
.) newsletter,
@C-LINK
, Volume 6, Issue 6, June 1989.
The Digital Track Display (
) is a hardware device utility I developed for the 1541,1541 clone and 1571 disk drives. My need for the
came about after many hours of experimenting with state of the art disk backup programs that didn't live up to their claims of being able to archive new software releases.
Tracker
interfaces to the disk drive via a 5 wire ribbon cable. It shows us the current track under the read/write head (including half-tracks) and lets us listen to sync bytes.
It consists of 1 pushbutton switch, 3 seven segment LED's, 11 IC's, and various support transistors, capacitors, resistors and a buzzer, all in a 6"x4"x2" externally (or in the case of the 128D ,internally) mounted project box. When loading a program it will show which tracks are being accessed, and listening to the buzzer will warn us if the track is abnormally synced. This is helpful if your archive won't run, to compare the archive to the original.
blanks the current-hungary 7-segment LED's after 20 seconds of drive inactivity to save power comsumption. It draws 123 ma. with LED's off, 190 ma. at rest with LED's on and 250 ma. max. when in full operation.
's primary function is to show us the
@bad
tracks or where the archive copy locks up. These tracks can have an abnormal number of sync bytes or a non-GCR format or errors in the header or any number of other protection schemes. With the
we can compare the archive copy to the original,so as to concentrate on where the protection
@really
Internally, the
@ DTD
is a little too complex to go into in depth here, so here's an overview. - I use the 2 control lines from the 4 phase head stepper motor to trigger monostable multivibrators that enable a binary decoder. At the time of the head step, the phase of the step is decoded and passed to the up or down inputs of the counters, depending on if it was a step up (higher track) or down (lower track). The outputs of the counter are decoded and displayed via 7 segment LED's. Safeguards are built in to protect from illegal
@phase skips
and decoding of tracks below 1 (also called head banging).
The pushbutton is for orientation of the
@ TRACKER
to the actual drive head position.Before working with any disk,the disk directory should be loaded and the button pushed to syncronize the
@TRACKER
to track 18.
Some of the parts listed here are available from Radio Shack, but most are not. I use Jameco Electronics (1-415-592-8097), Active Electronics (1-800-228-4836 or 1-800-228-4834), Digikey Electronics (1-800-344-4539) and Mouser Electronics (1-800-346-6873). Call these merchants for latest prices/catalogs.
Total project parts cost is about $35.00. Professional project cases are available from the aforementioned vendors as are kits to make your own PC boards. Prices for cases vary from $3.00 to $30.00, depending on your taste and/or budget. A friend of mine even built a hardwood walnut case for it.
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