[UncleOxidant]

I wonder if this would fit in a Lattice ICE40 FPGA so that Xilinx ISE could be avoided (very buggy) and open source tools like Yosys could be used instead.

[samlittlewood]

It will fit in an 8K easily. There was a version of the j1 (that this was based on) running on an IceStick with a 1K part. https://www.excamera.com/sphinx/article-j1a-swapforth.html

[howerj]

It should fit, as you said, but the last time I tried it the VHDL front-end for Yosys was not up to it. That might have changed as it was a few years ago.

[samlittlewood]

It is (I think) much better now - it is ghdl as a plugin synthesising to yosys IR. The nightlies from https://github.com/YosysHQ/fpga-toolchain have it all ready to go.