Re: commodore superpet mapping

From: Didier Derny <didier_at_aida.org>
Date: Wed, 2 Nov 2016 14:18:07 +0100
Message-ID: <c7aaeeeb-c094-bc12-d924-e666ddff40f6@aida.org>
btw  any way to use Vice with a french keyboard ?

tried many times and gave up...




On 01/11/2016 14:26, Rhialto wrote:
> On Tue 01 Nov 2016 at 13:53:03 +0100, didier derny wrote:
>> if I saw this machine in 1981, I never really had the opportunity to
>> play with it
>> Initially I thought the 6809 was running on it's ram and communicating
>> with the 6502...
>> (a bit like the madison zram with it's z80)
>>
>> recently I found the schematics of the superpet board (combined one)
>> Finally  (apparently according what I saw)
>> 1/  either the  6809  or the 6502 is running ?
> Yes, only one at a time.
>
>>        6809 stopped by the dma   ?
> There is a hardware switch which usually controls which cpu runs. The
> changeover actually happens during RESET, if I remember well. Although
> there is also a setting on the switch to control it by software.
> However that isn't implemented in VICE I think. I haven't seen any
> software which uses it, so there is no info coming from that direction.
>
>>        6502 stopped by shutting down the power  ?
>> 2/ the extra memory is only accessed as 16 page s of 4k in 9000 ?
> Yes.
>
>> 3/ it add a serial port
>>
>> 4/ a protection dongle
> The 6702, which was reverse engineered by this mailinglist and me.
>
>> Initially I thought the 6809 was running on it's ram and communicating
>> with the 6502...
>>
>> how are the rom decoded ?  I dont really understand...
>> the standard rom are only 'seen' by the 6502 ?
>> the extra rom only 'seen' by the 6809 ? and mapped at the same place ?
> Yes, each CPU sees only its own ROMs even though they are mapped to the
> same address range.
>
> You can play with it in VICE, select the SuperPET model, and find the
> Waterloo software disk images. The 6809 is not emulated cycle-exact, but
> it is fairly close and apparently good enough for the normal SuperPET
> software.
>
>> didier
> -Olaf.


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Received on 2016-11-02 14:00:07

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