Hi, here are some questions iam wondering about...
1. Can code be executed from anywhere? SRAM, $0x2000 etc.. I guess it should be treated as a normal read if this happens, like if reading $0x2002 and vblank flag is set, reset it. I guess this doesnt happen to often, is it a bad idea to just support code execution from $0-$0x1FFF, $0x4000-$0xFFFF ($0x4000 - $0x6000, treated as external RAM)
2. What happens if an increment from an absolute address occur in ROM and a mapper is used. Is it something special that happens or do the general code work? Load from ROM, increment it, Store to Mapper reg.
3. What exactly is it that can change the way the PPU renders the screen?
Most things seems to be disabled? Scroll can be changed right?, Control1 and Control2 can they be changed? Is it possible to disable rendering inside of a screen and change more things that is disabled during rendering?
thanks
1. Can code be executed from anywhere? SRAM, $0x2000 etc.. I guess it should be treated as a normal read if this happens, like if reading $0x2002 and vblank flag is set, reset it. I guess this doesnt happen to often, is it a bad idea to just support code execution from $0-$0x1FFF, $0x4000-$0xFFFF ($0x4000 - $0x6000, treated as external RAM)
2. What happens if an increment from an absolute address occur in ROM and a mapper is used. Is it something special that happens or do the general code work? Load from ROM, increment it, Store to Mapper reg.
3. What exactly is it that can change the way the PPU renders the screen?
Most things seems to be disabled? Scroll can be changed right?, Control1 and Control2 can they be changed? Is it possible to disable rendering inside of a screen and change more things that is disabled during rendering?
thanks