> Corrections welcome:
>
> 12 Resm0 ---- ---- Reset Missle 0
> 13 Resm1 ---- ---- Reset Missle 1
You misspelled "missile" a whole bunch of times. :)
> bit 6 bit 7
> 06 Cxblpf x000 0000 BL-PF -----
Small error here (it's present in the original stella.txt that you copied
this from too): BL-PF should be listed under "bit 7", not "bit 6".
> RIOT Memory Map
> 80-FF 128 bytes FREE Ram
>
> </PAGE 0>
>
> <PAGE 1> 180-1FF 128 bytes FREE RAM (used primarily as 6507 stack)
> </PAGE 1>
Remember that these are simply two ways of accessing the exact same
128-byte RAM area.
> <EXTERNAL MEMORY>
> Atari 2600 ROM Memory Map
>
> E000-FFFF 8K Rom
> (shouldn't this be EFFF-FFFF? this is an 8K range above)
Yeah, that's a misprint... E000-FFFF is the Atari's entire address space.
The upper 4k, F000-FFFF, is 4K Rom, also mirrored as shown:
> 1000-1FFF 4K Rom (mirror)
> 3000-3FFF 4K Rom (mirror)
> </EXTERNAL MEMORY>
> I am curious about something here. The 6507 has a 13-bit address
> bus. This comes out to 8192 bytes linear addressable. Don't these hex
> values jump around too much to fit within that address space?
Yep. 0000-1FFF is 13 bits, and is the entire 6507 address space. That's
why it's also mirrored at 2000-3FFF, 4000-5FFF, and so on... those
addresses are the same as the first address except with different values
of the 14th, 15th, and 16th bits, which is meaningless because the address
lines don't physically exist.
--
Archives (includes files) at http://www.biglist.com/lists/stella/archives/
Unsub & more at http://www.biglist.com/lists/stella/
