Coming back from a programming break over the holidays, I went back to work on my ST emulation… The CPU is making steady progress and for the first time the emulator ran through 1000 instructions without a hiccup.

It finally coughed up an exception on a bit shift operation about 1300 instructions into the TOS 1.04 that I’m using as my testbed. At that point a good chunk of the memory test of the Atari ST is over, and the system is about to figure out how much RAM is available.

Next up – initializing the video memory and a large number of system variables. That’s when things will get much more exciting on the system side of the emulation, and once my emulator runs TOS to the point where the video memory is being written to I can post some screenshots. I’m sure looking forward now to see as much as a few of the old bomb errors on the screen…