PDA

View Full Version : TEI MCS-CPU 8080 CPU Board



glitch
May 31st, 2016, 07:31 PM
I picked up a TEI MCS-CPU from Jeff Galinat at VCF East XI this year. It's an 8080 CPU board with onboard power-on jump, power-on reset, and MWRITE generation. Jeff didn't have any documentation on it, and I've been unable to find any online, other than mentions in sales literature. I took a little time tonight to go through it, figure out the onboard functions, and get it fully operational:

http://www.glitchwrks.com/2016/05/31/tei-8080-cpu

Neat little board, though TEI expected you to use the extra features (power-on jump, power-on reset, and MWRITE) in an all-or-nothing fashion: jumper J1 enables or disables everything. I wanted power-on jump and power-on reset, but didn't need MWRITE since I was using a front panel with it, so the writeup includes the trace cut modification I used to disable it. There are convenient vias on either side of the cut, so you can add in socket pins for a removable jumper.

The writeup also documents the function of the switches for setting the power-on jump address.

As I was working on this board, I noticed that the layout of the basic CPU function (excluding the add-ons) is *very* similar to the IMSAI MPU-A. Can anyone comment on this?