Changes
Z80
,/* Oddities */
* RST instructions are just a CALL instruction to a fixed address baked in the instruction itself.
* Despite what the syntax of the instructions JP (HL/IX/IY) suggests, PC will be loaded with the contents of the register itself, not the indexed value. Those instructions should be understood as JP HL/IX/IY.
* The 16-bit commands ADD HL,ss, ADC HL,ss and SBC HL,ss exist but not the command SUB HL,ss.
* While the syntax of ADD, ADC and SBC instructions all explicitly mention the A register, the SUB instruction does not mention it. On the Zilog eZ80, the SUB instruction explicitly mention the A register.
* IN r,(C) and OUT (C),r instructions syntax is misleading as these instructions actually use the full 16-bit port address contained in BC. On the Zilog eZ80, these instructions are correctly named IN, r,(BC) and OUT (BC),r.
* The Amstrad engineers chose to use the high byte of the address (register B) for chip selection instead of the low byte (register C) in I/O operations. As a result, OTIR / OTDR / INIR / INDR instructions cannot be used on Amstrad CPC for transferring or reading a sequence of values on a port as they use B as a counter.
