8-bit acorn emulators • Re: Beeb emulator on Raspberry Pi

I have recently acquired a Pi 400 and have set up a RetroPie image on it. It curious that the emulation of the BBC Micro seems to be missing from most of these multi-emulator suites, including Emulationstation which is used by RetroPie, whereas the usual options like C64, Spectrum, Nintendo etc are usually there. I wondered whether I could get a BBC Micro emulator running and came across a couple of B-em threads, including this one. I am considering purchasing the Pimoroni Pico VGA Demo Base and trying B-em on the Pico. However, in the meantime, ideally, I would like to get it running on the Pi 400 in RetroPie alongside the other emulators. I currently have PET and C64 emulation running and hope to add Amiga at some point.

The B-em source code program compiled just fine following the steps outlined here:

https://www.raspberrypi.com/news/emulat ... ry-pi-400/

However, it does not run. The produced error complains about a missing X display. I have had to take a photo and type out the text by hand:

Starting GUI thread
main: starting B-em v2.27-pi_x_drm
model: invalid rom setup type 'swram' in model 'BBC B w/1770 FDC, using 'swram' instead
ERROR(/home.johnc/src/b-em/src/pico/x_gui/x_gui.cpp:641): TODO: x_gui_setup_video()
Couldn't open X display
Aborted

I did notice a brief comment earlier in this thread that the B-em requires X, which, it would seem the RetroPie does not include. I therefore tried exporting the display to my Linux machine via SSH (ssh -Y) which does run X11, but this failed to run as well:

Starting GUI thread
main: starting B-em v-2.2?-pi_x_drm
model: invalid rom setup type 'swram' in model 'BBC B w/1770 FDC', using 'swram' instead
TODO: x_gui_setup_video()
ALSA initialized OK freq = 44100
Buf 2205 Period 552 ddnoise: unable to load stepo
model: starting emulation as model #0, BBC B w/1770 FDC
Using Pico ARM-ified ASM CPU on Pi
Loaded drive 0 with , format Acorn DFS, single-sided, 80 tracks, single-density, 10 256 byte sectors/track
libEGL warning: DRI2: failed to authenticate
Texture type = drm_prime
X Error of failed request: BadRequest (invalid request code or no such operation)
Major opcode of failed request: 154 ()
Minor opcode of failed request: 1
Serial number of failed request: 13
Current serial number in output stream: 13

Xeyes runs OK, so I know that the display is being forwarded correctly, but perhaps this is doing something the program was not expected to do.

So my question is whether it is possible to get B-em running under RetroPie on the Pi 400, or will to have to run under a separate full installation of PiOS? If it is possible to run it under RetroPie, then what are the steps? Are they documented anywhere?

Statistics: Posted by BitSeeker — Thu Feb 29, 2024 8:40 am

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