glitch
Veteran Member
I finished most of my IO-2 ROM/RAM board build over the weekend. It reads 1702A PROMs and can read/write a pair of 2101 Static RAMs as well. This allows me to read and archive 1702As (my Ohio Scientific equipment uses them) as well as testing 2101 SRAMs before using them in projects. Here's a picture:
I ended up using the 8212 8-bit IO port latches as data bus buffers, which worked out fine. The address decode and device select is pretty well-planned (at least I think!) and allows one to address any of the individual devices (4 1702As and the pair of 2101s) at any of the eight 256-byte segments that the board decodes. Here's the writeup:
http://www.glitchwrks.com/vintage/s100/io2rom.html
Thanks to Herb Johnson for burning the closest-to-the-bottom 1702A with a test pattern during the MARCH holiday party!
I ended up using the 8212 8-bit IO port latches as data bus buffers, which worked out fine. The address decode and device select is pretty well-planned (at least I think!) and allows one to address any of the individual devices (4 1702As and the pair of 2101s) at any of the eight 256-byte segments that the board decodes. Here's the writeup:
http://www.glitchwrks.com/vintage/s100/io2rom.html
Thanks to Herb Johnson for burning the closest-to-the-bottom 1702A with a test pattern during the MARCH holiday party!
