6x09 TFR / EXG Improvement (#10572)
Remove tuple implementation used by the EXG and TFR instructions of the 6809, 6309 and Konami CPUs. It was unnecessary because fundamentally these are implemented with a single, 16 bit wide temporary register.
Changed how the 6809 CPU processes the invalid 8 to/from 16 bit register combinations. Their behavior now matches actual hardware. I used page 66 and 138 of Darren Atkinson's 6x09 manual [1] for reference. I also double checked with my own hardware [2].
Checked for regressions using NitrOS-9 (6809 and 6309) on the CoCo, And Aliens and 88Games (Konami). |