6 Dec
2008
6 Dec
'08
8:08 p.m.
Thanks Tony, that should be enough info for me to see if I can get the
card to work. So the card will take both 27C256 and 27C512. I have
yes, but all the (EP)ROMs need to be of the same type
enough 27C256 on hand to stuff the board with those.
What is the HP marked IC 1820-2311? Is that the address comparator?
Yes. It's a 25LS2521, which is much the same thing as a 74LS688 (same
pinout). An 8 bit identity comaprator, here used to enable the card for
the approrpatie states of the high-order address lines.
I will have to create the EPROM tools disk and then take a look at
what info and tools are there.
Let me (us) know how you get on. I've never tried it.
-tony