Plugging a Sega powerstick or a snes joypad into a 3DO. NOT!
Info from Phil Burk, who works for 3DO Inc. (<firstname.lastname@example.org>)
Plugging a Sega, or any non-3DO, peripheral into the 3DO
control port can seriously damage your 3DO hardware. The wiring is not
because the 3DO control port uses a serial bus that also provides power
the peripheral. Sega peripherals are just switch boxes. Plugging a
peripheral into a 3DO box could, therefore, short the 3DO hardware.
The 3DO control port uses a serial bus so that it can support a number
of different peripherals all on one daisy chained bus.
The only way to adapt a third party peripheral to 3DO format would be
leave the existing 3DO peripheral electronics intact, and wire the
on the other device in parallel with the switches on the 3DO
Do NOT attempt this unless you are an experienced electronics hacker.
This will void the warranty on the peripheral and could easily
damage the 3DO unit if you make any mistakes.