Re: Ultimax questions

From: Groepaz <>
Date: Mon, 7 May 2012 18:27:11 +0200
Message-Id: <>
On Monday 07 May 2012, you wrote:
> Hello!
> This is related to mu ultimate C64 cartridge project ;-) The cartridge
> would boot itself in a Ultimax mode, so I would like to clarify some
> things about this mode (I don't have a C64 to check...):
> * The computer starts in Ultimax mode due to specific combination of
> /GAME and /EXROM lines. If the cartridge later changes these lines, will
> the computer go out of Ultimax mode, or stay there forever?

it will change immediatly, the respective lines are directly connected to the 
PLA of the c64.

> * Are the /ROML and /ROMH lines active on writes (so that we could put
> RAM there and write to it), or only on reads?

no, only on reads (except in ultimax mode). typically a cartridge that wants 
to map ram to these areas will reconstruct the CS signal from the adresslines 
and r/w.
> * How to start VICE in Ultimax mode? ;-))

by attaching a cartridge image (crt file) that is configured for it.

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Received on 2012-05-07 17:00:47

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