Sega Saturn Modchip + Switchless Mod + Dual BIOS!
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Seb's website can be found here for the switchless mod: http://seb.riot.org/saturnmod/
If your dual LED doesn't change much between orange and red, use a 180ohm resistor on the red side of the LED and a 680ohm on the green side.
The modchip can be found here: http://www.robwebb1.plus.com/saturn/s...
Here is a batchfile I made to compile the saturn bioses (make sure your bios files are named USA.BIN and JAP.BIN respectively): http://www.sendspace.com/file/n6wzl5
If you would rather use the windows command line, here's what you need to type:
copy /b USA.bin+JAP.BIN DUALSAT.BIN
When you get the output (dualsat.bin) load it in your EPROM burning software and perform a byte swap (don't forget this!) before burning to a 27C800 EPROM.
The pinout on the Saturn BIOS chip is the same as the 27C800, but the top two pins in the original BIOS are not used. Instead, you will want to leave pin 42 of the 27C800 disconnected and connect pin 1 to pin 10 of the PIC chip from Seb's mod (or if you get the jap bios for english games and vice versa, use pin 9 instead.) So connect pin 2 on the 27C800 to pin 1 on the motherboard, pin 3 to pin 2 etc.
Here is the pinout of the 27C800 EPROM if you need it: http://nintendoallstars.w.interia.pl/...
If you can't do this yourself let me know and I'll do you a chip for a small fee.
Enjoy and leave a comment if you need any help!