Day 2

A project log for AMD 2900 Chipset Research

Exploring the 2900 family bit slice chip set.

rey-mortaRey Morta 03/24/2020 at 21:260 Comments

One my first day at this I was able to communitcate with the chip and access some of the functioanlities. A lot of this was achived by straight out brute forcing the inputs of the chip and watching the result. While this was time consuming I did confirm functinallity of a few micro ops. 

This was done by setting the function to 0 for add and setting the carry pin high. I would set the source and destination values that I wanted to check with A port and B port 0. Then just pulse the clock. With certain settings this should create a counter. This was charted out on a spread sheet and varifed against the AM2901 data sheet. 

I was able to determin how to read and write to the ram and the Q registers doing this. Functions using the B address port of ram seem flakey.  More brute forcing is envolved.