Emulating a CSE should be possible - in fact, I started working on CSE support, but it doesn't work yet. I don't know about the CE - it's a very different design. It has a different cpu, and there's no ready-made ez80 core to use with your own IO code. In addition, the IO is very different from the CSE and earlier calculators. I think speed-wise it's not impossible, but it would be a much bigger undertaking than the CSE.