Re: Ultimax mode VIC II access to external RAM?

From: smf <smf_at_null.net>
Date: Fri, 4 May 2018 10:20:59 +0100
Message-ID: <3c87a177-5a5f-18e5-eba8-ea38d7d0392c@null.net>
On 04/05/2018 03:39, Mia Magnusson wrote:

> I've read somewhere that one of the decoded I/O select lines on a C64
> were once the decode for more memory on a MAX/UltiMAX. Maybe that is
> used instead of a real decoder in the MAX/UltiMAX basic cartridge?

IO2 doesn't exist at all on the Ultimax, IIRC it's used for a cia shift 
register pin.

IO1 seems to be the same $DE00 select on the Ultimax and C64, you could 
put RAM there but it's a bit out of the way.

I'd like to see a Max basic cartridge, but I'm guessing that it used 
it's own decoding. It's super trivial to and/or a few lines together.
Received on 2018-05-04 12:00:03

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