Post - Forum - Plus/4 World



	Home Search Games Tapes Covers Cheats Maps Software New Stuff Hall Of Fame HVTC Game Endings Solutions Remakes Publications Magazines Effects Top List Members Groups Features Plus/4 Encyclopedia Hardware Tools Options Forum Home Search Games Tapes Covers Cheats Maps Software New Stuff Hall Of Fame HVTC Game Endings Solutions Remakes Publications Magazines Effects Top List Members Groups Features Plus/4 Encyclopedia Hardware Tools Options Forum	Login

Forum Help

Post Your Message

Previous Messages

Posted By

siz
on 2007-12-10
15:31:45

Re: 1541 address decoding

You are absolutely right about repetitions. I'm not sure about the memory between $0800 and $17ff and i don't have a drive within reach to check.

But probably you are right after a quick check on schematics.

Posted By

IstvanV
on 2007-12-10
09:23:04

1541 address decoding

Does anyone know how this is actually implemented in the real hardware ? According to the schematics, there seems to be RAM at $0000-$07FF, 6522 registers at $1800-$1FFF, and nothing is connected to $0800-$17FF. This 8K area is repeated 4 times until $8000, from where the 16K ROM is repeated twice. However, in YAPE, there is RAM at $0800-$0FFF as well, and nothing at $2000-$7FFF. Until now, I used the latter version too (not having the hardware, I assumed that it would be correct), but in plus4emu 1.2.5 I made changes to use the layout guessed from the schematics. While this is probably not an important detail, it is easy to emulate correctly if I know what the correct memory map is.