Welcome to the Defender hardware identification repository, here you will find a collection of images and technical data for Defender PCBs collected into sets for a particular variant. Each PCB will also have notes on compatibility with other variants and links to schematics, SLICE projects and technical articles where available.
If you have any relevant PCBs that I do not have here I would be grateful if you would be able to take good quality photographs of both sides of them or loan them to me so that I can add them here.
The Defender early series boardset is limited to upright games only, the CPU and Interface boards cannot be used in a Cocktail game as they lack the hardware for screen rotation and player 2 controls.
The ROM, Sound and Power Supply boards can be used in upright or cocktail games and with the exception of the cocktail game restriction they can all be mixed freely with later series boards.
Defender boards cannot be used in any other game.
The Defender later series boardset imporves on the early series boards and adds the capability to play defender in a cocktail cabinet. All boards can be used in upright or cocktail games and can all be mixed freely with early series boards.
Defender boards cannot be used in any other game.
Williams Electronics licenced Defender to the Taito Corporation for the Japanese market.
The Taito Defender boardset comprises just two boards as opposed to the four from the Williams version. The CPU board is almost (but not quite) an exact copy, whereas the ROM, Sound and Interface boards from the Williams versions were combined into a single board.
Star Trek is a bootleg of Williams Defender, the boardset comprises two boards both with unique layouts:
The main board combines the CPU, ROM and Interface boards of a regular Defender boardset but only has space for 10 ROMs as opposed to the 11 ROMs found on Defender Red/Green ROMs.
The sound board is a clone of the Williams sound board with a different layout.
