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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Chain on July 13, 2006, 05:19:31 PM
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Hi all
:-D
I need to repair toccata soundcard, it have some problem with autoconfig. I replaced all IOs (even those which was not socketed - they are all socketed now :crazy: ), but its still not visible in early startup/showconfig. Also i cant see cards inserted ABOVE this card.
So now my questions for those hw gurus:
Is there any literature where i can find how autoconfig works?
There is a couple of books "amiga hardware reference guide" etc etc, but i will buy just one which i need (ebay perhaps).
How companies builds/projects cards from scratch? There must be something for it!
thanks for all advices
Chain
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You need the Amiga Hardware Reference Manual
The Autoconfig protocol and hardware requirements
are in Appendix G.
( it's a good read too )
Wol...
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There's some good info and examples for ZII stuff on the Dave Haynie Archives (http://www.thule.no/haynie/)
IIRC, Michael Bohmer/E3B had a detailed explanation of his ZII I2C card but I can't remember the URL
Chain wrote:
....but its still not visible in early startup/showconfig. Also i cant see cards inserted ABOVE this card.
Sounds like the PLD that handles the autoconfig is screwed, and so it doesn't pass on the config_in to the next card when it's finished its own config.
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Sounds like the PLD that handles the autoconfig is screwed, and so it doesn't pass on the config_in to the next card when it's finished its own config.
PALs are actually ok (tried in another card, and it runs fine, so there must be some invisible error in pcb traces.
zorro3 specs (http://www.thule.no/haynie/zorroiii/docs/zorro3.pdf) - looks good! i will read this first.
Thanks!
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some photos of rework progress on my site (http://chain.3dgrafika.cz/temp/toccata/)
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Sorry for OT but take a look at page A-6 in this ZIII Specification. It is a Glossary of Terms, take a look at term "cool". Haha. :lol:
/me hides again...
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_yak_ wrote:
Sorry for OT but take a look at page A-6 in this ZIII Specification. It is a Glossary of Terms, take a look at term "cool". Haha. :lol:
/me hides again...
there is also picture of Dave :pint:
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Chain wrote:
PALs are actually ok (tried in another card, and it runs fine, so there must be some invisible error in pcb traces.
Phew.. gotta be something annoyingly simple then.
Maybe one of the address latches or comparators is faulty?
Faulty ZII daughterboard?
Could be that the resistor pack is bad , so the '521 never generates an enable for the PALs?
Are you able check the output of the comparator to see if it ever does anything?
PS..Nice piccy of some ROMs on your site :-P
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Doobrey wrote:
Chain wrote:
PALs are actually ok (tried in another card, and it runs fine, so there must be some invisible error in pcb traces.
Phew.. gotta be something annoyingly simple then.
Maybe one of the address latches or comparators is faulty?
Faulty ZII daughterboard?
Could be that the resistor pack is bad , so the '521 never generates an enable for the PALs?
Are you able check the output of the comparator to see if it ever does anything?
PS..Nice piccy of some ROMs on your site :-P
No daughter board error (tested in 3000T, 3000, 4000, 2000) as another cards are working fine with the same slot/s
comparators are new, so are probably working :)
PALs are working in another card (tested), so now im stuck :boohoo:
resistor array was faulty (last resistor have >2megaohms, but it was marked 3K3) so it was repaired (added paralelly resistor 3k30 from bottom of PCB)
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SITUATION
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notice there isnt any other/not changed or tested ICs!
(only sound chip, which is working in another card too)
(http://chain.3dgrafika.cz/temp/toccata/toccata_14-07-stav.jpg)
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It looks like a nice simple autoconfig card, works just like the A2000's reference design card.
Have a look at this link (http://www.cdtv.org.uk/coldfire/A2000TRM_A2_a.png)(216Kb Png, large. Sorry, couldnt resize the png here)
It sounds like either the config in line is cut (pin 12) or the address bus lines are damaged in some way.
(Even if it doesnt latch the address the Amiga should still have a product number and all of that information.
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During referse negineering and measuring pin by pin ive found broken trace from Zorro pin 21 (adress line A5) to Autoconfig ROM (PAL1).
Now its soldered together (not really nice but works)
It was near zorro edge contact :( it looks like OK, but it was under nonsoldering green mask andhere was 450 ohms dry joint. Bah!
Toccata is now repaired, fantastic! :banana: :banana: :banana:
Thanks for all advices goes to (in no order):
Wol (point to good book, i still want to uy it)
Doobrey (point me to Dave Haynie!s archive, excellent source)
Oliver Hannaford-Day (also suggested broken adress lines, point to reference zorro card)
:pint: beer for all!
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Chain wrote:
Toccata is now repaired, fantastic! :banana: :banana: :banana:
Woohoo.. pivo time :pint:
Don't you just hate it when it's a stupid little fault like that :lol: