Memory maps, chip documentation
Posted: Fri Jun 13, 2008 10:41 am
MADrigal has collected some newsletters and books which contain small tidbits of the apparent creatiVision memory map. However I found it quite incomplete when I looked at it before. Does anyone have a complete map, or perhaps we could collaborate to put together one? It may be useful both for Basic programs and those of us interested in machine code, supposedly only runnable as a cartridge image.
While I'm onto the subject, I expected to find heaps of clear documentation on the TMS 99X9 series video chips. Maybe I looked in the wrong places, but I barely found anything. The least I'd like to see is a register map, but even better a few simple usage examples. For example can the video matrix be read or only written to? I realize both the video and sound chips are addressed through I/O ports on the cV, which is a pain in the *** to me compared to those computers and consoles which have memory-mapped chips. In particular as the creatiVision contains so little RAM and ROM there would've been plenty of space for memory-mapped I/O.
So, some good links to documentation on those TMS and SN chip are also welcome. I already know the 6502 CPU by heart and there are plenty of resources about it too. Looking forward to some good contribution, and the more resources we can put together, the more likely it is that other aspiring developers will find an interest in the creatiVision. After all, it consists of a (somewhat unusual) combination of well known chips. Ever since I read about these systems in the late 1990's, I've been fascinated about a 6502 based computer/video game with rich, flexible graphics and sound. Surely the C64, Atari 8-bit and so on are nice too, but given how many Z80 designs used the 99X9 series video chip to great success, I like to see it paired with a "real" CPU.
While I'm onto the subject, I expected to find heaps of clear documentation on the TMS 99X9 series video chips. Maybe I looked in the wrong places, but I barely found anything. The least I'd like to see is a register map, but even better a few simple usage examples. For example can the video matrix be read or only written to? I realize both the video and sound chips are addressed through I/O ports on the cV, which is a pain in the *** to me compared to those computers and consoles which have memory-mapped chips. In particular as the creatiVision contains so little RAM and ROM there would've been plenty of space for memory-mapped I/O.
So, some good links to documentation on those TMS and SN chip are also welcome. I already know the 6502 CPU by heart and there are plenty of resources about it too. Looking forward to some good contribution, and the more resources we can put together, the more likely it is that other aspiring developers will find an interest in the creatiVision. After all, it consists of a (somewhat unusual) combination of well known chips. Ever since I read about these systems in the late 1990's, I've been fascinated about a 6502 based computer/video game with rich, flexible graphics and sound. Surely the C64, Atari 8-bit and so on are nice too, but given how many Z80 designs used the 99X9 series video chip to great success, I like to see it paired with a "real" CPU.