I uploaded the Split Second raw ROM dump and a rearrangement like the TMS1100, but with every other column of 16 bits treated as chapter+2 (that's just a guess without trying to disassemble the resulting code; it could easily be that the chapter+2 column comes first). There are about 7 obscured bits that I'll double-check after removing the top metal layer.

www.seanriddle.com/splitsecondraw.bin

www.seanriddle.com/splitsecond.bin

I'll document the hardware tomorrow.

"Ahhh, what an awful dream. Ones and zeroes everywhere... and I thought I saw a two."