search

GideonZ / 1541ultimate

Official GIT archive of 1541 ultimate II sources
GNU General Public License v3.0
178 stars 45 forks source link

Feature request : create fake vic address in UII+ #230

Open ciccior2003 opened 3 years ago

ciccior2003 commented 3 years ago

As I know in U64 there is $D031 address for turbo mode, I would to know if it is possible in UII+ to create new address clone. Example : $D032 -> $D016 ; $D033 -> $D016 ; $D034 -> $D017 ; $D035 -> $D018 ; $D036 -> $D011. In this example using a 5 bytes string with REU could be possible to have FLI mode and SideBorder with sprites.

Thanks

GideonZ commented 3 years ago

Dear Ciccior,

This is not possible in the way you portray it, because the U2+ does not send the address to the VIC normally. However, you could make a modified REU which does something like that. Those addresses would then only exist when a write is done from the REU, not from the CPU. E.g. REU -> Address Translation -> Cartridge Port But... this is not just a quirk, but quirk squared! :-) Those addresses would then only exist when a write is done from the REU, not from the CPU.

Gideon

ciccior2003 commented 3 years ago

Hi Gideon,

It would be nice if from c64 it was possible to program a sequence of addresses directly on U2 to hack REU. Then, using $ DF0A on bit 5 (not used) it was possible to perform hack address sequence on REU with standard stripe data. I don't know if the UII+ speed by adding this code on the REU emu is enough to not waste the execution time of a real REU. Let me know.

Ciccioriccio