An exciting development

[surixurient]

Over at assemblergames user jhl has dumped the sh-1 rom and reported that he knows how to load code from the mpeg card slot.

http://www.assemblergames.com/forums/showthread.php?52419-Saturn-CD-Block-ROM-dumped

 

[ExCyber]

That's pretty cool. If I understand it correctly, the basic method had occurred to me a few years ago, but I didn't have any real idea whether it would work and didn't have a Saturn board I was willing to sacrifice. I wonder if a closer analysis would reveal any interesting bits that could be exploited without custom hardware...

 

[antime]

Same here, except I had planned on making a card for the MPEG slot that interfaced with an FPGA board. You'd have to lift one of the boot mode pins, and connect that and the CS0 pin to the card, but I think that's the only hardware modifications needed (provided that the CD block ASIC doesn't need special configuration to pass through the data pins). Since toggling the boot ROM seems simpler than I expected, you wouldn't need an FPGA, just some flash and an external data port.

 

[vbt]

jhl did a great job !