Does anyone know which pins in the megadrive cartridge slot activate compatipablity for master system games and what state they must be in?
I know it doesn't need any extra electrical components to activate because I have an adapter that only changes the pinout.
Please include the physical location of the pins so there is no confusion.
Any help will be much appreciated.
I have this info written down on a bit of paper somewhere...I'll have a look for it tonight.
When I last looked at this I was trying to work out what would be needed to connect a rom to the cart port and have the mega drive read from it in normal mega-drive mode and in master system mode by just flicking a switch. My notes are messy but here's what I can tell you....
Refer to the gamesx megadrive pinout.
Pull B30 low to put the console into master system mode (Soft reset is a misnomer). This line is normaly held high by a pull up resistor. When in master system mode some of the cart pins change function....i'll make a table.
PIN| NORMAL| MS-MODE|
xx A1-15 A0-14 (no change, just different names)
B06 A18 !CE
B17 !CE A15
B11 A23 PAUSE (input! low = paused)
B09 A21 ??? (pull high, dunno why)
Everything else should be as you'd expect. I have not investigated the other unused address pins.
Thanks a lot for the info it has been very helpful.