Recent Posts

SN76489: Success and Failure

Trying to get the SN76489 working has been an interesting exercise and a good example of why it is important to read datasheet with great care. Initially I ...

A small update

It’s been a while since I’ve done any work on this project. I was going to build, or at least part build a second board to see if I could get the V9990 worki...

DRAM and IDE

The last couple of weeks have mostly been spent working on improving the monitor code but there has been some progress on the hardware side as well. Both th...

YM2151 Sound

Getting the sound working turned out to be easier than expected and managed to get the YM2151 playing music fairly quickly. To get some music playing I used...

Monitor ROM

Y Ddraig now has a ROM based monitor program to speed up development and debugging. It’s based on the zBug monitor by Wichit Sirichote. The ability to...