GSBarnDoor

The GSBarnDoor project (http://www.gsbarndoor.com/), also called just "Barn Door" or "IIgs Barn Door", was a collaborative project between James Littlejohn of 8bitsystem.com and Henry of ReActiveMicro. Henry's involvement started in May of 2011.

The GSBarnDoor was to be a kind of CPU Replace Board for the IIgs, and allow 32bit processing.

History

Henry was contacted and asked if he would like to help with the project since he had contacts at VLSI Concepts (http://vlsi-concepts.com). They could could provide a licensed, working core based on their existing designs.

Henry and the owner of VLSI Concepts would work together to provide a working CPU replacement based in an FPGA. James Littlejohn and Henry would then use the CPU replacement design as a bases for the GSBarnDoor project.

The core that VLSI Concepts was providing did 8bit, 16bit, and also allowed for 32bit processing based on the WDC 832 CPU datasheet. They completed their IP core around November 2011, and it has been available since then for license.