Re: Disassembly of the Z80 ROM of the C128

From: Marko Mäkelä <*msmakela_at_gmail.com*> Date: Sat, 25 Feb 2017 15:38:46 +0200 Message-ID: <20170225133846.22vmyqdmjrc2ra6i@hp> · msmakela_at_gmail.com

On Sat, Feb 25, 2017 at 12:58:06PM +0100, Ruud@Baltissen.org wrote:
>Is there a disassmbly of the Z80 ROM of the C128, used to boot CP/M, 
>available?

Actually the whole C128 boots up with the Z80. If I remember correctly, 
the Z80 is checking the C= key and the -GAME and -EXROM inputs of the 
MMU, deciding whether to switch to the C64 mode. Another (redundant) 
check is done by the 8502. I happen to know this, because I made some 
minor tweak to my C128 startup. I cannot remember what that tweak was, 
but I guess that I could dump the ROM to find out.

	Marko

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