Re: ZX81 ROM ?

I also have some of these 2564 eproms by TI and I do have an old eprom
burner that will program them. Pin for pin compatibility makes them ideal
for replacing a bad ZX81 ROM but with a little more effort you can install a
lower power 28 pin 27C512 EPROM programmed with a bunch of DIP switch
selectable ZX81 operating systems.

Or if you rather turn on than switch, glue a 74HC173 Quad latch on top of
the EPROM and you can use the ZX81 keyboard on power up to select 1 of 7
operating systems you wish to boot from.

Mmmmmm..... multiple operating systems

"Peter de Vroomen" <peterv[at][spamblock]jaytown[dot]com> wrote in message
news:42dfd531$0$90381$e4fe514c@xxxxxxxxxxxxxxxxx
> > There may have been 2564 chips but if so they were not often seen.


.

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