How much z80 and how much 8080 ?

Enlighted (4155)

20-09-2019, 14:27

Hi all. To those have put more in contact with BIOS and MSX-BASIC in MSX's ROMs how much old 8080 code is here?
had M$ Guys took the idea of using z80 instructions to take advantage of z80? What about CP/M?

By nikodr

Paladin (750)

20-09-2019, 15:07

I think this explains something about z80 and 8080a
http://www.msxarchive.nl/pub/msx/mirrors/hanso/datasheets/ch...

By Eugeny_Brychkov

Paragon (1232)

20-09-2019, 15:36

MSX BIOS and BASIC is 8080 with some tailoring for Z80.
https://retrocomputing.stackexchange.com/a/6283/8258
Note that you MUST preserve routine entry addresses as many applications are calling them directly, thus space saving will be questionable.