That's much clearer. I have a board that looks like that. It has a 1984 date on it. That MOS7709 chip is Commodore's version of the 74LS258. The PLA has the following on it: 93459 DC F 8407 SINGAPORE The 93459 is Fairchild's version of the 82S100. It once had a paper label on it, but it kept falling off. I finally got tired of gluing it back on and threw it out. Just a reminder: only real programmable PLA's like the 82S100 or Fairchild 93459 have logic terms that can be read by a programming device. With mask programmed logic arrays, you can only read the output. On Wed, 21 Apr 1999, Sam Laur wrote: > > The picture is slightly blurred, but I can make out the National > > Semiconductor logo just below the Commodore logo. I checked their web > > site, but could not find any information that applied to this chip. > > You're right it is blurred, because what looks like the curly N, is actually > "25" ... so here's a picture, bigger but with better resolution hopefully : > http://users.utu.fi/slaur/pla2.jpg (47k) > > > It looks as though 251064 is a valid part number for the early '80s. > > So, the mystery continues. I probably should somehow obtain a dump of its > outputs, but currently I don't have the hardware to do that. > > - > This message was sent through the cbm-hackers mailing list. > To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tcm.hut.fi. > - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tcm.hut.fi.
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