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Old 26th Apr 2021, 8:49 pm   #1782
ortek_service
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Default Re: Non-working Commodore PET 3016

Quote:
Originally Posted by PJL View Post
An epic repair with 1770 posts. Having watched this thread from near the start and having been in electronic design and programming using early 8 bit CPU's back in the 80's, you almost had me longing for a pet...but the number of faults has thankfully cured me of that.

I don't think all PET's will have suffered so many different IC failures (I seem to recall it may have got upto 20 on Colin's list!)
- and not quite sure what happened to this one (If all the RAM IC's had failed, some Commodore-specific ROM's then that may have been less surprising, as these don't always have to great a reliability compared to most simple TTL IC's)
However, original PET's are currently rather collectable & fetching rather-high prices, so they are now still well worth repairing .

But you could always build a modern clone (still using the same original main IC's types, but using modern CMOS versions that are still being sold in DIL and a lot simpler RAM without lots of obsolete IC's), for not too much.
And probably managing to eliminate quite a few of the original buffer IC's that had been responsible for many of the problems on this one.
- Like the one I recently saw in this article that featured new clone design, smaller PCB: https://www.eevblog.com/forum/projec...programmer/75/

It's a lot closer hardware-wise to an original, so should allow you to use all the addons, compared to just using an FPGA dev board / RPi or a PC to emulate one at software-level.

Last edited by ortek_service; 26th Apr 2021 at 9:01 pm.
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