[Coco] About those EPROMS...

[Stephen H. Fischer]

Trying to understand how the ROMs were made that were execute only I cannot fetch from my memory. The method did not last long. 

Dumping the EPROMs we are discussing never had any protection. By the time we got to 27128 they may be more the same. My memory started with the first EPROMs and after 2-3 size increases I lost interest beyond how a programmer could be made.

Just a few pins on a Synertek 6522, a few serial to parallel shift registers.

The SYM-1 programmer I wired made use of many 6522 data lines, there are four 6522 VIAs thus 8 x 8 bits available on the connectors. I never made it as I got my first CoCo.

I feel sad whenever a project is started using a 6821 PIA. The Synertek 6522 is so much better and is much more than two eight bit (Unprotected) data registers.

SHF