Not strictly an accelerator but close enough! :) The Gemini was an attempt to build a multi-processor card designed for use on the Zorro III bus which contained two mini A3000s with 030's and 68882s as well as memory which would run a custom copy of exec. The Gemini could access all Zorro III memory and Chip RAM and each CPU could access the memory of the others. The board shown contains no CPU, FPU or RAMSEY. The board requires a Rev 11 buster since it uses "client" mode which allows it to be used as a board controller.

Thanks to Dave Haynie