Saturn CD Block ROM dumped again.

rorirub

New Member
One detail I noticed from the schematics is that the LSI can handle both the 20- and 21-pin interfaces, meaning that Sega were planning to use two different CD chipsets from the start.
Worth noting that on a machine that uses CDB106 and a 20pin drive (CDB106 normally always uses 21pin drives), pin 87 of the SH1 is jumpered to +5V instead of ground. The documents list this pin as the least significant bit of the Port C data register. Anyone bothered to look into what the CDB firmware does with those registers?
 

Waterfuell

New Member
Worth noting that on a machine that uses CDB106 and a 20pin drive (CDB106 normally always uses 21pin drives), pin 87 of the SH1 is jumpered to +5V instead of ground. The documents list this pin as the least significant bit of the Port C data register. Anyone bothered to look into what the CDB firmware does with those registers?
My research is based on CDB105 and unfinished, so i cant help, the only that i can say about port C is that pin PC6 is config as analog input AN6 in pin 94
 
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