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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment. |
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12th Aug 2015, 4:07 pm | #1 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
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CBM 8032 faults
In another thread which was closed by the moderators because it had drifted, there was a brief mention of Commodore 8032 (and other PET) faults.
Now while I don't like the idea of 'stock faults' [1] there are a couple of things that spring to mind... The first is that Commodore seems to have used the cheapest and worst IC sockets they could find. I have fixed a number of PETs by replacing all the IC sockets with nice turned pin ones [2] The second is that IIRC the 8032 uses 2114s as the video memory. A less reliable chip I have yet to find. If you end up with odd video problems, stuck bits, repeated characters, etc, check and/or replace those. It doesn't matter who made them, or what machine they are in, those 2114s are suspect. I've fixed a lot of machines -- Commodore, TRS-80, HP, etc, etc, etc which have had bad 2114s. [1] Stock faults are OK if you keep on seeing the same type of device and can quickly find the fault in perhaps 90% of them by going down a list of a dozen common problems. They are much less use when you have one item when Murphy's Law will ensure the fault is not on the stock faults list. [2] Worse, in the Whitechapel MG1 workstation, the 32016-series CPU, FPU, etc were in turned pin sockets. The EPROMs were in cheap sockets. Replacing the EPROM sockets fixed the 2 MG1s that passed over my bench. Last edited by AC/HL; 12th Aug 2015 at 8:03 pm. Reason: Forum rules |