itch.io

Got it, it does not work on my sega nomad, I will try your method, thank you

that trick didnt work for me, no matter what, I cant boot the game with a flashed cart, only early genesis 1 model, others fail to boot, including nomad

This does not work for me.  Also weird that it could work because the Sega does not hold state between power cycling!?
Only way i could get it to boot is to use a Game Genie in between. Which is kinda unacceptable as it makes it dependent of that Game Genie cart (if that stops working, you're stuck with a none booting Metal Gear game cart)

I start to believe that it is a hardware timing issue with the cartridge (at least my copy which looks and feels super high quality btw). When power comes on the cartridge is still initializing/booting itself when the Mega Drive gives it control too soon. This explains why game genie in between works, because then the metal gear cart gets power and can initialize itself before it is given control to really boot.

The metal gear cartridge seems too slow on startup to be ready.