I am starting to program in Saturn and wanted to know if it is possible with the use of the ram cartridge to dedicate it`s ram for slave cpu and master cpu to be with all the main ram so that slave cpu does not have to wait master cpu when both need to access the ram.
Ram cart + Slave cpu
- Thread starter ClaudioSH2
- Start date
I don't know where I saw this, but I'm pretty sure that prohibition is only there because it was seen as a potential security hole. That explains why it says not to do it even if you transfer the code back to internal RAM first. Still, you have to wonder why Sega prohibited developers from doing this when the BIOS itself runs code from a cartridge...
I notice it every time I turn on my Saturn with the Action Replay cart in it. 😉
That could be, but I think fundamentally any security issue is in the usage of the bus, not in what type of memory is expected to be attached to it, so I still think that's the more likely explanation. A corrupt data structure (e.g. a level map or a palette) could be about as much of a hazard to the gameplay experience as corrupt code, wouldn't allow an attacker to take over the system as easily. To be honest I don't see what it is particularly that they were afraid of, but I also don't see what could be a threat for ROM cart usage and not RAM cart usage - if you're assuming an attacker the game can't assume that a particular type of memory is connected in the first place.
CyberWarriorX
Established Member
I'm not sure about the other versions of the bios, but on the jap 1.01 the actual code starts at 0x00001A62. It basically does an ip check at 0x22000000 then if all is good, it executes the code pointed to by the ip.
Cyber Warrior X
