28 Aug
2007
28 Aug
'07
8:01 p.m.
On 28 Aug 2007 at 22:10, Dave Dunfield wrote:
Btw, for an ultra-simple EPROM emulator, use one of
the
Dallas NVRAM chips (DS1225 (8K) , DS1235 (32K) etc.).
Stuff it in a RAM socket of a convienent SBC to program
it, and make an adapter by piggybacking a couple of sockets
and moving the necessary address lines, mask write etc.
to plug it into a ROM socket.
...or for a 2764, you could probably do the same with an FM1808 FRAM
substituted for a 2764 (write 4 copies of the data) or 27128 (write 2
copies of the data). P/ maps to WE/ on the FRAM. Pin 1 (Vpp) either
high or low (but not at the programming voltage) is a don't care, as
long as it's at 0 or 5v.
Or so it appears to me.
Cheers,
Chuck