lidnariq wrote: ↑Sat Oct 24, 2020 7:20 pm
Ok: the correct question I
should have asked is: do we have any insinuation of another PCB that's mapper 525 that actually has a VRC2 on it? Or are the writes to $A000 just an incomplete mapper hack?
Probably incomplete hack, original game always use two consecutive 8k banks
$8000=PPP0
$A000=PPP1
to form one 16k and the pirate port just reacts the write to $8000, ignoring the lower bit so they did not even have to modify the ROM.
If they had VRC2 chip, they wouldnt bother with all those discrete chips.
When VRC2+discrete chips appears, it is a sign of:
* VRC4 game, using the chips to extend its capabilities to provide IRQs and 0/1 mirroring
OR
* VRC2/VRC4 multicart game, like the one below