Jos Dreesen / Marian Capel wrote:
How about a NV SRAM, such as the DS1220? 100
nsec, 24-pin JEDEC
pinout. Or an ST M48Z12, same-oh pinout and capacity?
These look like the best option.
Are you trying to replace something like an 82S191?
Indeed , I have a CPU with 40 bit wide microword (5x 82s191).
I would like to replace the instructions for read sector, write sector
and set track.
Target is to use an IDE drive instead of the original cartridge drive.
Jos
The CY7C264 (UV EEPROM 8Kx8 24p/600mil, 45-55ns) is a direct drop in
replacement for the 82S191. The two extra chip selects on the '191 are
upper address lines on the '264; just alias your '191 image four times,
and drop in the '264.
CY7C264 can be found on ebay most any time. A typical good price is
$4-$6 each in small quantity.
Don
AK6DN