So those asics would somehow need to be simulated to even read the carts? So how does naomi conversion get past that? What about maybe software solution inserted in the memory at boot up or something?
Ill just ask directly,So even if you some how get past this are atomiswave to dc conversion even possible?
it is slightly easier in case of NAOMI, because game medias is similar in general, they are both ROM boards (or DIMM board),
as of porting in general, there should be done such tasks:
- cartridge simulation. should be found routines which do cart data access and replaced with calls to Dreamcast GD-drive read syscalls. this expected to be hardest task, especially in term of making fast enough sound or video data streaming.
- players inputs. expected to be easy enough task, since at logical level ROMEO works almost the same as regular Dreamcast controller but with shuffled buttons order, and this order should be patched/fixed.
- coin inputs. they are read from MMIO at G2 bus area (8bit mode). these should be patched and "routed" to data read from Maple access routines above, or patch games to enable "free play" mode and not require coin inputs.
- SRAM access. Atomiswave have battery backed 128KByte SRAM inststead of DC's flash ROM, and used to store game settings, play stats, high scores, etc. this probably should be fully removed / patched out, because DC have no such NV memory.
- flash ROM (BIOS) access. some of games do checks if BIOS area are really flash ROM (sending there CFI/JEDEC commands), mainly for protection reasons. this should be located and disabled/patched too.
Also, Atomiswave is always listed to have 8 mb ram of sound ram compared to dc 2 mb.
this is obviously wrong, anyone interested may google for Atomiswave PCB photos, read AICA RAM chip part number, google its datasheet where will be said it is 2MByte, same as regular Dreamcast.
this is typical internet curse - at some point was spread incorrect information and then was copy&pasted everywhere. happens quite often these days.