Re: SuperCPU for my C64 and C128

From: smf <>
Date: Mon, 23 Jul 2018 22:54:26 +0100
Message-ID: <>
On 23/07/2018 21:34, Mia Magnusson wrote:
>> 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.
> The speed of the VIC-II reads won't be a problem, it's just a matter of
> inserting one wait state for the 65816

You'll be doing bidirectional memory accesses across a bus where both 
sides run off different clocks.

I'm not saying it can't be done, but you have to do it & there will be 

>> 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.
> Will 6510 based demos work at all on a 65816? I'd assume that they use
> some well known illegal op codes?

You misunderstood, I am talking about 65816 demo effects.

I don't know how many 6510 demos use illegal opcodes, but none of my old 
demos used them though.
Received on 2018-07-24 00:00:46

Archive generated by hypermail 2.2.0.