COLLIER-1 Memory Map

Feb 1, 2013

I’ll have 64Kb of address space to play with on the COLLIER-1, and this is how I plan on playing with it, from bottom to top:

12Kb ROM / EEPROM: There are versions of CP/M which run on the 6800 processor, so I’m hoping to implement a BIOS and CP/M in this lower memory area. The 6809 is source-compatible with the 6800, so conversion shouldn’t be an issue.

4Kb IO.

32Kb RAM: I’ve got some 8Kb static RAM chips from RS Components. They should do the job!

16Kb Video RAM: 16,384 bytes will give me a 200 x 160 pixel-mapped display in four colours! It’s not exactly SVGA, but what can you do? I’ll also want to have another mode, for text. At 80x25, a normal terminal, this will give me 8 bytes per character - plenty of room to add colour information. I’ll be able to define foreground colour, background colour, with 256 available for both. Which is plenty. :-) There will even be room for a memory-based character table, so games will be able to use this mode with some graphics, if they’re simple enough.