Thanks for the help. Now I managed to make one board to work. Only minor
issue, every 16th column shows garbage on the upper half of the screen. I
suspect one of the 2114 display RAM. The question is now how to detect which
one to solder out? The one with an output pin always on high, right?



-----Original Message-----
From: owner-cbm-hackers@ling.gu.se [mailto:owner-cbm-hackers@ling.gu.se] On
Behalf Of Ruud@baltissen.org
Sent: Wednesday, May 06, 2009 7:10 PM
To: cbm-hackers@ling.gu.se
Subject: Re: 8032-sk with extra memory on Supersoft high resolution graphics
board

Hallo Anti Florian,


> I have two 8032-sk computers, both not functional.

The way I repair most of my systems is starting to swap IC's with a working 
device until that one stops. This device doesn't need to be the same as the 
system under repair. So you can use a 1541 drive to test the 6502 and 6522 
for example. 
A tip: the 6545 can be replaced by a UMC 6845 or an Hitachi 6845. _NOT_ the 
well known Motorola 6845. Don't ask my why.

The ROMs can only be tested with another, same system. Using an EPROM 
programmer you can check them on their contents. Be aware, twice I ran into 
an EPROM with the correct contnets but probably outputting it too slow.

A osciloscoop is nice but not sufficient for repairing computers.

A nice tool would be a logic analyser. Unfortunately more then just a bit 
expensive. So I made a single-stepper that makes the 6502 to execute its 
program byte by byte: http://www.baltissen.org/newhtm/debugger.htm . It 
enabled me to repair many 6502 and 6510 based systems.


--
    ___
   / __|__
  / /  |_/     Groetjes, Ruud Baltissen
  \ \__|_\
   \___|       http://Ruud.C64.org







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