VOGONS


First post, by majestyk

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Rank Oldbie
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Oldbie

For decades I´ve been using this Floppy / IDE controller that was built in 1991 for testing all kinds of mainboards.

The attachment CCAT200A_1.JPG is no longer available

It almost always worked smoothly without rejumpering - until I accidentally pulled it out of a system that was still on.
Afterwards the floppy-controller was no longer recognized.
Just for fun I replaced the floppy-controller chip and three 244/245 buffer-circuits - to no avail.
Now there´s just the odd PAL - a "PAL20L10ANC" - left plus two 74xx that appear to belong to the IDE section.

So far I didn´t manage to make my trusty "TL866 II plus" address or read the programming of this chip.
What could I do to test or replace this component??

Reply 1 of 1, by rasz_pl

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Rank l33t
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l33t

First step would be a logic analyzer and checking activity on chips. PAL seems to be used for address decoding, you can trace where pin 3 of wd37c65b is going and start there.

https://github.com/raszpl/sigrok-disk FM/MFM/RLL decoder
https://github.com/raszpl/FIC-486-GAC-2-Cache-Module (AT&T Globalyst)
https://github.com/raszpl/386RC-16 ram board
https://github.com/raszpl/440BX Reference Design adapted to Kicad