Re: Hardware emulation of 6509 using 6502?

From: smf <smf_at_null.net>
Date: Thu, 26 Jul 2018 04:10:15 +0100
Message-ID: <f9c237d8-f8c8-8881-f9d0-942501edd3bb@null.net>
On 26/07/2018 02:18, Mia Magnusson wrote:
> Oh. But that must be the kind of software no-one wants to run? ;)

Someone wants to run pet software?

> Well, a cbm2 has hardware that's similar enough that I assume most
> productivity software for PET would work.

I'm not sure the basic & kernal is even compatible enough for that. 
Should be simple to try some programs in vice.

> Emulating a VIC 20 would require something like an interrupt routine
> copying a 22*23 screen onto the 40*25 screen and translate the VIC
> registers, or just let basic programs without most pokes/peeks run by
> just inserting a line feed at position 22.

Make the kernal output stop at line 22 and patch the basic PEEK/POKE 
commands to remap the screen coordinates.

You'd stick vic in a higher bank so that you can start vic 20 basic 
programs at the right place.

You could add a timer to catch screen writes by assembly programs, I'm 
not sure it's worth the hassle.

>> http://sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?t=468
> Seems like a bad idea :)

Probably, isn't everything commodore 8 bit related a bad idea?

Porting the vic20 emulator to the p500 seems like a very bad idea.
Received on 2018-07-26 06:00:05

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