Re: SuperCPU for my C64 and C128

From: Luis Rene Vela Garcia <lrvg1010_at_gmail.com>
Date: Fri, 20 Jul 2018 08:02:24 -0500
Message-ID: <CAG5RqJUSxSv3rjmb-uzh2dfo16X1cAarCN3QdyA7KKbNTv9pEQ@mail.gmail.com>
So you can turn off mirroring of certain ranges.

http://ftp.giga.or.at/pub/c64/supercpu/superprog.html

If you add an ultimax mode then you still have to mirror ram at the
start of memory, but you have to solve the problem of interleaving the
1mhz vic reads into the 20mhz cpu reads.

Thank smf, i will check it.

El vie., 20 de jul. de 2018 5:31 AM, smf <smf@null.net> escribió:

> On 20/07/2018 07:11, Baltissen, GJPAA (Ruud) wrote:
> > Are you sure that this happens with the SCPU as well?
>
> It doesn't, by default it mirrors writes to the first 64k
>
> This slows the super cpu down, because it can run software at 20mhz but
> if two writes happen one after the other then it has to wait for the
> first 1mhz write to complete.
>
> So you can turn off mirroring of certain ranges.
>
> http://ftp.giga.or.at/pub/c64/supercpu/superprog.html
>
> If you add an ultimax mode then you still have to mirror ram at the
> start of memory, but you have to solve the problem of interleaving the
> 1mhz vic reads into the 20mhz cpu reads.
>
> You still need to support all the supercpu mirroring schemes as well, or
> you won't be able to get the correct timing for demo effects.
>
>
>
Received on 2018-07-20 16:00:05

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