Re: Re: CP/M programming for the C128?

From: Greg King (
Date: 2003-02-15 03:35:48

-----Original Message-----
From: Baltissen, R (Ruud)
Date: Tuesday, January 28, 2003, 03:31 AM
> > Then, do the disk stuff in 6502-mode, and return to z80 CP/M
> > when done.
> AFAIK, that is the way how CP/M on a C128 accesses the drives.
> But, I never understood why.  The only reason I could think of
> is that it simplifies programming, by using existing code.

When Commodore sold CP/M for the C64, they wanted to leave as much room as
possible for application programs.  They didn't want to waste space by
duplicating code in the BIOS.  So, they used the Kernal ROM to communicate
with all devices.

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