08-18-2020, 04:18 PM
Some questions:
1) Why the JP 56?
2) You do exx but do not push /pop the EXXed registers?
Ah, one more thing: after discussing with other "hardware geeks", all agreed that the value should be always $FF in the table so, as you suggested, only the last value is taken into account. The thing is that only "bugged" (i.e. very old Kempston interfaces) places random (non $FF) values in the Bus, but well designed ones don't. So...
1) Why the JP 56?
2) You do exx but do not push /pop the EXXed registers?
Ah, one more thing: after discussing with other "hardware geeks", all agreed that the value should be always $FF in the table so, as you suggested, only the last value is taken into account. The thing is that only "bugged" (i.e. very old Kempston interfaces) places random (non $FF) values in the Bus, but well designed ones don't. So...