Saturn CD Block ROM dumped again.

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?
 
In SS service manual there is a schematic wich helps to get a global idea how CDB is composed.
But not show the line wich SH1 uses to send comands to CD drive.

You can see it on this picture.
 

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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
 
Are you still working on this? Any progress? I'm interested in making my own ODE because hardly anybody can afford the prices they charge and we can control microcontrollers with python now so I thought I would give it a shot. I've ordered a few Saturn's to use for testing and will probably start getting my hands dirty with the project at the start of the new year. Essentially my goal is to get a cheap ODE on the market for everybody.
 
Are you still working on this? Any progress? I'm interested in making my own ODE because hardly anybody can afford the prices they charge and we can control microcontrollers with python now so I thought I would give it a shot. I've ordered a few Saturn's to use for testing and will probably start getting my hands dirty with the project at the start of the new year. Essentially my goal is to get a cheap ODE on the market for everybody.
The project is halt, looks like ROM has been reverse engineered other times before, and people say there is no more to extract.
The theorical feature that should be interesting to find is the way to load SH1 encrypted code from an autorized cd, but RE all the ROM requires lot of job for something that doesnt arouse much interest.

At this moment Im also working on a open source ODE, ive talked about it whith other users in discord, not so deep, bu you can take a look if interested.
 
The project is halt, looks like ROM has been reverse engineered other times before, and people say there is no more to extract.
The theorical feature that should be interesting to find is the way to load SH1 encrypted code from an autorized cd, but RE all the ROM requires lot of job for something that doesnt arouse much interest.

At this moment Im also working on a open source ODE, ive talked about it whith other users in discord, not so deep, bu you can take a look if

I saw that it had been reversed before but I thought the information was still not fully publicly available.
Sent you a message on discord.
 
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