Game Gear:Controller Port Mod
Pxlmod Technologies (Francis Bernier) created a mod board to mount a Sega Genesis controller in a Sega Game Gear, ideally for use with a TV-out mod kit.
You can purchase the kit from locations such as Console5 or VideoGamePerfection.
Installation
A full installation guide can be found File:Game Gear Controller Port Mod.pdf.
The solder points are as follows for the various motherboards.[1]
VA1 837-9024
Up: C32 (top pad) Down: C33 (top pad) Left: C34 (bottom pad) Right: C35 (bottom pad) Start: C38 (right pad) I: C36 (bottom pad) II: C37 (left pad) +5V: C11(+) GND: C11(-) (alternate) +5V: C1(+) GND: C1(-)
837-7719-01
Up: C24 (bottom pad) Down: C25 (top pad) Left: C26 (bottom pad) Right: C27 (bottom pad) Start: C30 (right pad) I: C28 (bottom pad) II: C29 (left pad) +5V: C6(+) GND: C6(-)
Majesco VA5 837-10766
Up: C20 (left pad) Down: C21 (left pad) Left: C22 (bottom pad) Right: C23 (bottom pad) Start: C26 (bottom pad) I: C25 (right pad) II: C24 (bottom pad) +5V: C1(+) GND: C1(-) (alternate) +5V: C33(+) GND: C33(-)