I have been on a bit of an 8-bit bonanza on the Ulx3s ECP5 board and have now implemented the following retro computers and consoles: ZX Spectrum, Vic 20, TRS-80 Model 1 (and Video Genie), MSX 1, ColecoVision, Sega SG-1000, Cosmac Elf, ZX80 (only partly working), Gameboy (only slightly working), Acorn Atom, BBC Micro, CP/M, Jupiter Ace, Apple 1. The platform also has the Apple 2, Orao, Galaksija, NES, TI-99/4A, Ti-99/2 and Altair 8800.
If anyone is keen on having anyone of these or any other 8-bit computers (other than the ones already available), on the Blackice Mx or the Blackice II board, I can have a look at it. Porting to the ECP5 is easier as there is much more BRAM available and it can be dual-ported. On the Blackice boards more use of SRAM or SDRAM is needed.
On the ECP5, for most of these computers and consoles, games can be loaded from the SD card via an on-screen display (OSD). This would be harder on Blackice boards but may be possible with some firmware development.