8080 Assembler-Text Editor (ATE)
bfranchuk at jetnet.ab.ca
Fri Apr 21 12:25:17 CDT 2006
Holger Veit wrote:
> I know of a least one software (which I had disassembled myself for
> curiosity long ago) that actually uses undocumented Z80 instructions,
> namely the ones that allow access to the higher and lower haves of the
> index registers: this is the 12K-Zapple-Basic by TDL. Concerning these
> instructions, they seem to work on most common Z80s, including Z80A, B,
> and H variants, tried those myself. I haven't verified, due to lack of
> HW, where they also work on the 64180, the z180 or z280.
I think I have read that some versions of floating point routines
made use of the un-documented instructions. One version of Small-C
for the Z80 made use of this.
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