Upgrading the video chip to V9958

A project log for Steckschwein

A 65c02 based homebrew computer

Thomas W.Thomas W. 03/20/2018 at 12:550 Comments

Like the 9929 board, the all new, all more powerful video board based on the mighty Yamaha V9958 chip has two parts – the video chip part with the 128k video memory (64k x 4 DRAM this time) and the signal part, using the Sony CXA2075M chip not only as RGB output stage, but also to generate composite video and s-video. This should increase the number of Steckschwein-compatible monitors a big deal.

The V9958 is the successor of the V9938, which in turn is the successor to our TMS9929/9918, which has served our project for quite some time. But it is hard to ignore what the V9958 has to offer (80 column text mode to begin with), so we decided to use it as the first major upgrade to the Steckschwein Hardware specs in a couple of years.