Steve, Keep in mind that I am guessing on the PROM based on the limited number of 128k 28 pin PROMs available at that time. That's a pinout for the NEC PROM but I don't know if that is the actual part which was used. There should be a number on the chip that may lead to the answer.
Kurt -----Original Message----- From: M100 [mailto:m100-boun...@lists.bitchin100.com] On Behalf Of Stephen Adolph Sent: Sunday, February 19, 2017 5:13 AM To: Model 100 Discussion <m100@lists.bitchin100.com> Subject: Re: [M100] Parts for an NEC PC-8300 .. comparing a 27C1001 pinout to the one from Kurt, it looks like it may just be possible to stuff a 27C1001 and wire up only a couple of signals. On Sat, Feb 18, 2017 at 8:12 PM, Stephen Adolph <twospru...@gmail.com> wrote: > come to think of it, you could probably tie /CE and /OE together. > > On Sat, Feb 18, 2017 at 8:08 PM, Stephen Adolph <twospru...@gmail.com> wrote: >> I did not grasp how much information is in that 500MB tech reference >> doc for the 8300. Wow! >> >> probably the best documented Model T. >> >> It is clear that the ROM is 128KB, and I think it is also clear that >> without some custom solution, one can't make a replacement main rom >> for the 8300 easily. At best you might be able to program a 27C1001, >> and then do a custom adapter board. >> >> A normal eeprom needs both a chip select and an output enable, so >> some extra logic might be needed too.
