AT27C256's should be fine, as the programming is pretty much a "one time" issue. Crusty's newer software loads the bios.hex file from the SD card so changes to the Eprom should be rarely if ever needed.
or/ I'd be happy to program a 27C256 for you.
I also have a Needham's EMP-20 I'd sell/swap. It's dos based, but a solid well made unit that programs most of the 27xxx series.
On 1/27/2015 10:09 PM, Todd Miller wrote: