Re:The Z80's feature discovered after 40 years [video]
by flohofwoe on Monday October 17, 2022 @05:10AM
(#33231282)
After a little while you know the most common opcodes without having to look them up, I still have some burned into my brain forever:
LD HL,nnnn: 21 nn nn
LDIR: ED B0
JMP nnnn: C3 nn nn
CALL nnnn: CD nn nn
RET: C9
...etc..., and probably dozens more after getting back into the groove :)
Re:The Z80's feature discovered after 40 years [video]
by Tepix on Monday October 17, 2022 @06:29AM
(#33231702)
I only remember NOP from x86 assembler: $90
Re:The Z80's feature discovered after 40 years [video]
by 0xf00ff00f on Monday October 17, 2022 @11:02AM
(#33234459)
Wow, I've just remembered C3, CD and C9. What a blast from the past!
Re:The Z80's feature discovered after 40 years [video]
by rwmj on Monday October 17, 2022 @05:18AM
(#33231336)
The ZX81 & Spectrum manuals had a big table of opcodes in the back so it wasn't too bad. Most of them you memorized after a while. See page 94 here: http://www.retro8bitcomputers.co.uk/Content/downloads/manual...
Other Z80 computers did have pretty capable assemblers, even with simple macros as I recall.
Re:The Z80's feature discovered after 40 years [video]
by mrspuratic on Monday October 17, 2022 @07:16AM
(#33232025)
This was the tersest possible listing of opcode mnemonics :/
I cobbled together a basic understanding from various machine code listings (Toni Baker, Your Sinclair IIRC), and my "assembler" was paper, pencil and a FOR/INPUT/POKE loop...
My uncle loaned me a Sharp MZ700 one summer, its manual had a detailed breakdown of Z80 opcodes (in mere 4 pages) which was a revelation to me, and an annotated monitor in assembler. https://archive.org/details/sharpmz700ownersmanual (p160-)
I started with the 6502 on the C64, the Z80 came much later when i wrote some trainer patches for Gameboy ROMs.