Re: How (does?) SuperCPU 64 control CPU port?

From: Jim Brain <brain_at_jbrain.com>
Date: Mon, 24 Apr 2023 13:33:23 -0500
Message-ID: <8df92880-b22f-c11b-3723-cf735bf5baf6_at_jbrain.com>
On 4/23/2023 7:27 AM, Maciej Witkowiak wrote:
>
> I assumed that '816 remains in control all the time. It doesn't have a 
> port so $00/$01 writes should appear on the bus like any other access 
> - this can be intercepted and latched somewhere on the SCPU side.
As groepaz notes, SCPU just precludes tape.  And yes, as you note, the 
'816 remains in control, so the internal 6510 register never gets updated.
>
> That's what I think too. There was no HW mod on C64. Since SCPU had 
> JiffyDOS built-in, which already drops tape support, maybe it was 
> implied that it doesn't work. I suppose the kind of C= users who could 
> buy SCPU didn't bother to play with cassettes anymore.
Yep.  The lack of tape on JD made it trivial to bypass the argument.

Jim



-- 
Jim Brain
brain_at_jbrain.com  
www.jbrain.com
Received on 2023-04-24 21:00:08

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