I have been slow getting round to porting any 8-bit computers to the Blackice Mx, as it is easier to port them to the Ulx3s. On that board, I have added a few more retro computers, including the QL and the Mac Plus (both 68000 machines), and i am currently working on the Sega Master System.
It is harder to get the Beeb working on the Blackice Mx, than the Acorn Atom, because of the way it uses RAM, but with changes that @hoglet made for other boards, I think it is now possible to use SDRAM on the Blackice Mx and get to HDMI working on the Ulx3s (where my port currently only supports VGA). Doing this is not very high on my priority list, but I might get round to it sometime.
On Blackice boards, I am currently more interesting in using nmigen and in using the n6800 nmigen implementation of the 6800 cpu. Variants of that (such as the 6809 or 6803) are used in computers such as the Tandy Coco, Dragon 32/64, Tandy/alice MC10, etc.
It is a pity that more people are not working on getting retro computers working on a variety of open source boards. @emard, the creator of the Ulx3s board nearly has the C64 working. That board has far more retro computer implementations working on it than any other open source board.
Of course the board with the most retro computer implementations by far is Mister, but that is not an open source board, and does not use the open source toolchain.
It is quite hard to convert Mister implementations to open source boards, as it uses a lot of VHDL, and its host processsor runs Linux and is much more powerful (and more tightly coupled to the FPGA) than the host processor on the Blackice boards. But with the Yosys GHDL plugin, it is becoming easier to convert Mister cores. @daveshah1 got the SNES core at least partially working on the Ulx3s board using GHDL, and @emard is doing the same for the C64. The Blackice boards are probably not powerful enough to run SNES, but a C64 implementation using SDRAM is probably possible.
Another computer I want to work on soon is the Amstrad CPC.