there is an unused ROM, I think it contains a 2nd stage layout for the game, and appears to be banked in after you finish a bonus round, however, even hooking it up as a banked rom the game crashes, and the data in the ROM looks suspicious (there are flipped bits at fairly regular offsets even in 0xff fill areas) It could be the bank hookup is wrong, but the data concerns me enough to mark the rom as BAD_DUMP. We need another PCB to dump the Colour PROM anyway, although we've only seen it once.
Frogger (videotron bootleg) [system11]
not yet marked as 'working' because I want to investigate this a bit more (and need to fix up the inputs)
there are 2 z80s on the board, but no sound code roms for the 2nd z80, the PCB does have sound. hustleb3 seems to be the same hardware and we assumed the sound roms to be missing, but based on this new evidence they're not, so I need to revisit that one too.
timers seem very active, does some DMA ops (transfering a big block of 0 data) a few times on startup, then stops.. maybe because no interrupts happen.
interrupt table looks.. weird, need to understand how it configures the interrupt controller and what that means.
there are port writes to low port numbers, writes to port 0x0000 in the format with data in the format
0x??00
0x??01
0x??02
0x??03
0x??04
0x??05
0x??06
0x??07
0x??08
0x??09
0x??0a
0x??0b
0x??0c
0x??0d
0x??0e
0x??0f
0x??10
0x??11
0x??12
0x??13
0x??14
0x??15
0x??16
0x??17
0x??18
0x??19
0x??1a
0x??1b
0x??1c
0x??1d
0x??1e
0x??1f
and after each write to port 0 with those values it writes some other data to ports 2,4,6.
if the information is correct, and this is a 32-channel based sound system, then that could well be some kind of configuration for the channels.
note, it does now write the 'for use in Japan' message to one of the tilemaps, but you don't currently see it, either due to timing or video emulation issues
