This might be clearer than my rambling http://www.oxyron.de/html/registers_mmu.html On 07/05/2018 20:56, smf wrote: > I believe.... > > Writes to PCR registers are the same format as the CR register, you > write to them but mapping doesn't change until... > > Writes to LCR register tells it to load from the corresponding PCR > register into the CR register. It's so you can quickly switch between > banks without having to keep calculating the CR register or passing it > around. > > So PCRA can be the CR for where code is, PCRB could be the CR for > where the kernal reads/writes from. The kernal then only needs to know > to hit LCRB, perform the access and hit LCRA. > > On 07/05/2018 19:31, Jim Brain wrote: > >> https://ia801002.us.archive.org/10/items/Compute_s_Mapping_the_Commodore_128/Compute_s_Mapping_the_Commodore_128.pdf >> >> >> I see the registers, but I'm not sure I understand the PCR and LCR >> regs. Is there a document that explains these? >> >> Jim >> >> >Received on 2018-05-07 22:00:03
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