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Keyboard/Gamepad Interface v1.0 fix

For Mega Drive version ONLY

While the NES flavour of the Keyboard/Gamepad Interface board works flawlessly, a bug is present on the MD version v1.0 revision of this board. Please use the workaround described below:


This workaround is for the Mega Drive version of the Interface; do NOT apply these mods to the NES version.

  • Disconnect pin 11 of U9 in the Interface board (either bending or cutting the IC's leg, or by removing the corresponding socket pin -- this pin should be NOT in contact with the board.
  • On the back of the board, make a bridge between pins 11 and 12 of U9, as shown on the pictures below.

Mega Drive interface fix

Bent pin 11 on U9 (74HC86)

Mega Drive interface fix

Solder bridge between pins 11 and 12


This fix allows operation of a MD controller pad, although C and START buttons will be swapped.


All of these issues are already fixed on revision v1.3 or later.