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Back to forum Reply To This Topic Go to last reply First Back Next Last 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. 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. Back to top Reply To This Topic Copyright © Plus/4 World Team, 2001-2013