WIP: 16C firmware hack for more memory

[brouhaha]

(04-06-2023 04:53 AM)brouhaha Wrote:  One of the possible issues is that the code uses status register bits 4, 5, 6, 7, and 8, and this may interfere with the 16C's normal use of those status bits. I need to find somewhere to save the status bits before executing the new functions, and restoring them afterward.

I switched the status bit usage from what was in the 10C to that of the 41C, in particular to not use status bit 8, so that I can save and restore status bits 0-7. That does seem to have cleared up quite a few issues. e^x and 10^x are still returning 10x the proper value. I probably need to compare traces of e^x operation on the hacked 16C microcode vs the 41C.

I started adding the 41C y^x code also, but I haven't got it hooked up to a 16C operation yet. I need to figure out how best to handle two-operand instructions, for y^x, P->R, and R->P. I haven't even started merging and debugging the trig code yet, so P->R and R->P are still some ways off, but y^x should be easy to get working once e^x is working.