> On 2019-09-22, at 21:37, Mia Magnusson <mia_at_plea.se> wrote: > >> 2 issues: >> >> * Some of the newer DIS replacements use those addresses >> * The MMU needs far more than 4 addresses, unless I switch to >> indirect registers (IO1 is the address, IO2 is the data), but I'd >> prefer not to do that. > > Perhaps use extra addresses in the VIC-II address space? (Not sure if > anything bad happens if you touch those addresses though). It will conflict with the upcoming "Beam Racer" VIC "copper-style" extension. > Maybe you could put registers in the $FFxx range like on the C128, with > enable/disable in the regular I/O space. While I understand the reluctance, "indirect" registers is probably the most viable, least "invasive" approach. The concept's been used in some chips of the time (and I didn't like it too ;-) -- SD! - https://e4aws.silverdr.com/Received on 2020-05-29 22:41:06
Archive generated by hypermail 2.3.0.