Hi it's interesting it looks simpler that I expected... I have 2 projects: one is to make a board with the following functionalities - something like the 6502 rom/ram board extended to implement the 64k extension I could also extend it to support the superpet ram (enough ram available in one chip) - vga output - usb keyboard the idea is to have all the fonctions I need with a small board connected between the cpu and the keyboard connector... one is to make a 6809 board in fact I could have both processor 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. Message was sent through the cbm-hackers mailing listReceived on 2016-11-01 20:00:23
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