I would love to see a BBC Micro core in libretro. I have requested that the core be added via Github Request to get a BBC Micro \ Core added to RetroArch · Issue #13108 · libretro/RetroArch (github.com) and on Discord but no one has ever taken up the development, hence I would like to offer a bounty to incentivise someone to make this happen. The BBC Micro is one of the greatest machines ever made and was instrumental in kicking off the computer gaming industry in the 1980s. Acorn Computers also went on to become ARM - the source of most RISC chip designs today.
I’d like to see a core with the standard libretro features plus an on screen keyboard screen for handhelds. There are several open source emulators available today: BBC Micro emulators - Emulation General Wiki (gametechwiki.com) Beebem or B-em being 2 obvious choices. I even have support from the Beebem creator to port it. There was also a great port for RG350M devices which added in a virtual keyboard: jeremyrayner/beebem-rg350: Port of the GP2X/RS97 version of beebem to the RG350 handheld console. (github.com) Recalbox have a version of Beebem running with save states etc but it has no sound: BeebEm | Recalbox Wiki
I am willing to pay the bounty of £200 or $250 to whomever completes this task. I can’t seem to access The site is temporarily down (bountysource.com) at the moment to post it as it is down. I also know there are other people interested in supporting this core addition.