Beeb emulator on Raspberry Pi

[julie_m]

I made a "universal" .deb of BeebEm a while back; which ought to work on anything Debian or Ubuntu-based, including a Raspberry Pi:

https://earthshod.co.uk/beebem_0.0-13_all.deb

It pushes the envelope of the packaging system a little bit

[lchile]

This binary is great but I can't get the emulator on the Pico to recognise the SD Card. I have renamed it to Disc 0 but only the embedded demos are found not the SD Card. What am I missing?

To answer your question.... it is finally here!

And very nice indeed...

I had a couple of build issues on Ubuntu 18.04, but both were easily resolved:
- I needed to install ruby
- I needed in install gcc-8 and g++-8 to be able to compile the embed_tool and then set the GCC and GXX env variables to point to /usr/bin/gcc-8 and /usr/bin/g++-8 repectively. The issue that tripped up the older gcc was the #include <filesystem> which I think is still a bit non-standard.

I've had a go at adding SD Card support, so that we can access the vast SD card libraries of Beeb Games.

Here's a few photos of it running:
IMG_2200.JPG
IMG_2202.JPG
IMG_2203.JPG
IMG_2204.JPG
IMG_2205.JPG
IMG_2206.JPG

I took a few wrong turns in the process of doing this:

My first attempt was to use one of the hardware SPI interfaces that are built into the RP2040. But then I realized the SD Card on the VGA Demo board is not wired correctly for these (any idea why?)

My second attempt was to use a PIO SPI interface - but then I realized you are already using both PIOs for Video and Audio. I don't know if it would be possible to squeese these into a single PIO, so that an SPI interface could be loaded into the other?

So finally I resorted to using a version of MMFS that bit-bangs SPI in 6502 code. This is the version we use with the Beeb/Electron printer port. It makes the code you need to add to the emulator very mininal:

Code: Select all

static volatile uint8_t port = 0;

uint8_t mmc_read(uint16_t addr) {
   if (gpio_get(PIN_MISO)) {
      return port | 0x80;
   } else {
      return port & 0x7f;
   }
}

void mmc_write(uint16_t addr, uint8_t val) {
   port = val;
   gpio_put(PIN_CLK,  port & 2);
   gpio_put(PIN_MOSI, port & 1);
}

The only disadvantage of this version is it's a bit slow - about half the speed of using a hardware implementation. If you can think of a way to squeeze in a PIO SPI interface it's probably worth doing that. It will need a different build of MMFS, but that's straightforward to create.

This is currently Master only - the only reason being that it's harder on the Model B to support multiple file systems without PAGE being raised, which means nothing works. I did wonder whether seperare CMake builds for DFS and MMFS might be the way forward. But that's beyond my CMake pay grade!

I've just pushed this to a branch in github, and generated a pull request if you are interested in including it:
https://github.com/kilograham/b-em/pull/1

Dave

[hoglet]

This binary is great but I can't get the emulator on the Pico to recognise the SD Card. I have renamed it to Disc 0 but only the embedded demos are found not the SD Card. What am I missing?

Can you give a bit more information as to which "binary" are you running?

[lchile]

Sorry - using your binary as posted below.

my vga demo board needs this!! Would you be prepared to release a binary release of your build hoglet?

Here's a zipped .uf2 file for the BBC Master version with SD Card support:
master.zip

This is compiled with the USB Keyboard option enabled.

(Graham said this wasn't working, but I've not had any issues with it and it means the system is standalone.)

You will need a USB-OTG cable to allow you to plug a USB keyboard into the micro-USB port on the Pico:
https://thepihut.com/products/usb-otg-h ... o-a-female

Then you need to power the system from the USB power socket on the VGA Demo Board.

Dave

[hoglet]

Sorry - using your binary as posted below.

I've just checked that, and it's working fine for me.

Are you getting a Card? error, or something else?

The problem is likely either:
- the connections between the Pico and the SD Card
- your SD Card

Can you post an photo of the setup, so I can see some more details?

Are you using the Pimorani Pico VGA Demo Base?

What size is the SD Card and how was it formatted? It should contain a file called BEEB.MMB.

I have renamed it to Disc 0 but only the embedded demos are found not the SD Card.

This makes no sense to me. What exactly have you renamed?

Dave

[lchile]

Many thanks - got it to work. Never used a BBC Micro emulator before so didn't know that should have been supplied in BEEB.MMB. Found one that works mostly, get lots of Bad Program errors which might be to do with Master model incompatibility? Also a lot of screen corruption which might be to do with the USB implementation? Still Exile and a whole slew of programs do work so am very happy, thank you!
Just to confirm: was using Pimoroni VGA Demo Base, Pico W and a SanDisk 32gb SD Card formatted to FAT32.

Sorry - using your binary as posted below.

I've just checked that, and it's working fine for me.

Are you getting a Card? error, or something else?

The problem is likely either:
- the connections between the Pico and the SD Card
- your SD Card

Can you post an photo of the setup, so I can see some more details?

Are you using the Pimorani Pico VGA Demo Base?

What size is the SD Card and how was it formatted? It should contain a file called BEEB.MMB.

I have renamed it to Disc 0 but only the embedded demos are found not the SD Card.

This makes no sense to me. What exactly have you renamed?

Dave

[lchile]

Everything I have tried has worked from this version of beeb.mmb on hoglet's version of kilog's Pico build, thanks:
viewtopic.php?p=415647#p415647

[BitSeeker]

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?

[Duglor]

I am running a b-em emulator on raspberry pi 4.71 retropie from an trusted anonymous source.

I will attach the .sh here in a zip file here to this msg.

Place it in
/home/pi/RetroPie-Setup/scriptmodules/emulators
or place it in :
/home/pi/RetroPie-Setup/ext/RetroPie-Share/scriptmodules/emulators

when you run setup and experimental options...there then becomes an option to install it.
f11 brings up menu
ALT-ESC quits back to emulationstation.
The emulation works though keyboard only unless the game supports joypad. It's odd.

Can anyone tell me what the following values refer to...I do not have any document that has these values. Seems there are very many variations.

Here's my current b-em cfg for it. It runs in 800x600 for some reason with the gamma a bit dark.

b-em-allegro4.zip

b-em sh file to place into retropie setup dir and then install with experimental modules.

(1.93 KiB) Downloaded 19 times

mouse_amx = 0
key_as = 0
vdfsenable = 0
ideenable = 0
scsienable = 0
displaymode = 3
ddtype = 0
ddvol = 2
cursid = 2
sidmethod = 0
soundwave = 0
soundfilter = 1
sndtape = 0
sndddnoise = 0
snddac = 0
sndmusic5000 = 0
sndbeebsid = 1
sndinternal = 1
tube6502speed = 1
tube = -1
model = 3
defaultwriteprotect = 1
disc0 = /home/pi/RetroPie/roms/zxspectrum/B/3D Grand Prix (1984)(Software Invastion)[h TSTH].ssd
video_resize = 0
fullborders = 2
fasttape = 1


a tiny explanation or link to what each of these means would be helpful.

[BitSeeker]

Thank you for posting that. I will give it a try.

I had noticed some notion of a .ssd file. What are these please and how do I generate them? I still have an .MMB file with a lot of stuff from a long time ago. Can this be converted, or will B-em read the .MMB as well?

[Duglor]

.uef is the format of a game cassette file. .ssd is the format of game disk file. These are the only two formats that work with this emulator. no zips or anything..

[Duglor]

Thank you for posting that. I will give it a try.

I had noticed some notion of a .ssd file. What are these please and how do I generate them? I still have an .MMB file with a lot of stuff from a long time ago. Can this be converted, or will B-em read the .MMB as well?

You'd have to google about conversions. It won't work with an .mmb file.

[BitSeeker]

Looks like there might be a program called MMButils that might be able to convert .MMB to .ssd. In the meantime, is there any documentation that explains the parameters in the example configuration that you posted. I couldn't find any on either the Stardot Github or any of the other B-em or BeebEm repositories. Some of the parameters are self-explanatory, but not all.

Also, the script refers to Allegro 4, but the current version is 5. The version on the Stardot repository appears to require 5. Will this be automatically downloaded, or do I have to upgrade it after installation? I presume that since this version is based on Allegro, it is different from killograham's optimized pico version?

[Duglor]

Can't really help..perhaps you can search at retropie.org.uk/ forum...

Looks like there might be a program called MMButils that might be able to convert .MMB to .ssd. In the meantime, is there any documentation that explains the parameters in the example configuration that you posted. I couldn't find any on either the Stardot Github or any of the other B-em or BeebEm repositories. Some of the parameters are self-explanatory, but not all.

Also, the script refers to Allegro 4, but the current version is 5. The version on the Stardot repository appears to require 5. Will this be automatically downloaded, or do I have to upgrade it after installation? I presume that since this version is based on Allegro, it is different from killograham's optimized pico version?

[GreyAreaUK]

Disclaimer: this probably won't work. But...

You might like to give the attached Windows 10 app a try. It's something I was noodling around with some time ago, but never finished. It's very, very alpha-phase software, it'll probably crash rather than work, and for the love of Zod use a COPY of your MMB file!

Having said all that - it can in theory do what you want, albeit one disk at a time.



Once you run the app, click LOAD and point it at your MMB file (copy!)

Once it's hopefully populated the grid (and not just crashed) you can simply drag any disk image out onto the desktop, and it'll (hopefully) create an SSD file of that disk.

Or you can right-click and choose 'Export'



Note: if the MMB file contains anything other than SSD (DSD images for example), it'll probably crash because I never got around to handling those!

It's very crashy, shall we say?

[scruss]

Also, the script refers to Allegro 4, but the current version is 5. The version on the Stardot repository appears to require 5. Will this be automatically downloaded, or do I have to upgrade it after installation? I presume that since this version is based on Allegro, it is different from killograham's optimized pico version?

RetroPie tends to run on a much older version of Raspberry Pi OS (Debian 10) than is current (Debian 12). It may not even have Allegro 5 available. I have a RetroPie console somewhere, but I'm not sure if it's current (or even where it might be) to test.

Please don't get any version of b-em that runs on the Raspberry Pi Pico (a very tiny microcontroller) confused with b-em that runs on a Raspberry Pi. Their requirements are very different.

sweh's MMB utilities live here: MMB/SSD Utils in perl. You can probably extract all the SSD files in an MMB using its dget_ssd command

[BitSeeker]

Thank you for the additional information and references if conversion software.

Disclaimer: this probably won't work. But...

You might like to give the attached Windows 10 app a try. It's something I was noodling around with some time ago, but never finished. It's very, very alpha-phase software, it'll probably crash rather than work, and for the love of Zod use a COPY of your MMB file!

Having said all that - it can in theory do what you want, albeit one disk at a time.

Once you run the app, click LOAD and point it at your MMB file (copy!)

Once it's hopefully populated the grid (and not just crashed) you can simply drag any disk image out onto the desktop, and it'll (hopefully) create an SSD file of that disk.

Or you can right-click and choose 'Export'

Thanks for suggesting it as an option.

Please don't get any version of b-em that runs on the Raspberry Pi Pico (a very tiny microcontroller) confused with b-em that runs on a Raspberry Pi. Their requirements are very different.

Yes, I am aware that the Pico is different from the Pi. I have done some programming on the Pico and was intrigued that a BBC emulator could actually run on one. I am looking at that as a separate project. The kilograham version is said to be "optimized" and apparently runs very well on the later. The build does require the Pico SDK but compiles for both the Pico and Pi 400. I got it to compile on the RetroPie installation, but can't replicate that on my separate test installation using the latest 32-bit PiOS.

sweh's MMB utilities live here: MMB/SSD Utils in perl. You can probably extract all the SSD files in an MMB using its dget_ssd command

Thanks.

I have also been trying to compile the version hosted on the Stardot Github which runs on Allegro 5, on this same test installation. The compilatiom appears to have been successful, but am not sure how to start it? The crucial piece of information regarding how to run the emulator seems to be omitted from the otherwise helpful Overview/readme.

[scruss]

The command name is b-em. I have no idea how Retropie starts things, alas.

[BitSeeker]

I am not running the Startdot version (with Allegro 5) on RetoPie, but the latest 32-bit lite version of PiOS. Indeed, I tried running ./b-em first but that tells me that the program is unable to start a display. Since xorg was installed as one of the dependencies, I tried startx to fire up the GUI, but that just hung. Do I need to install the full desktop environment?

BTW, at the moment IDK either how RetroPie starts things, but it does not seem to have X installed.

[BitSeeker]

So I tried installing the full GUI environment with:

Code: Select all

sudo apt install raspberrypi-ui-mods

Unfortunately that didn't work and GUI would still not start, so I ended up re-imaging the SSD with the latest 64-bit full version of PiOS add starting again. Once again, the version of B-em on the Stardot github compiled just fine and this time, it also ran when started from a terminal window. At least I now have the Stardot version running on a separate installation. Next step is to try loading some programs.

I also tried compiling the kilograham version again, but still no joy. It seemed to compile fine on the RetroPie setup so I guess it needs an older version of PiOS.

It would be nice to be able to get it to run in RetroPie so I need to go back to the script posted by Duglor. I hadn't realised that RetroPi runs on a significantly older version of PiOS. I appreciate the clarifications and accept that I will have to run the older version based on Allegro 4.

[scruss]

I see you're (maybe?) getting help in the RetroPie forum. They know the deal, I don't.

Acorn BBC Micro Emulator (current?) - RetroPie Forum

[BitSeeker]

No, not me, but I guess I have hijacked this thread a little.

I have now got both the BBC Micro and Master emulators running under Retropie thanks to that script posted by Dulglor, so thank you for that.

[scruss]

Oops, sorry for the mistaken identity, but glad that you got it going via the RetroPie forum

[ash73]

I find it bizarre there is no straightforward Beeb emulator on the rPi, given it's the spiritual successor. I recently bought a Pi5 and it won't even run RISC OS now (requires OS with 64 bit kernal). I like playing with BBC BASIC on the Pi, that works fine and I supppose it's 80% of the fun... but I used to like dabbling with 6502 assembler too.

BeebEm on the PC is perfect but I'd rather run it on a Pi, feels a bit more authentic somehow? Still toying with the idea of buying a real Beeb, but I think it would end up gathering dust, and it's a bit of a minefield buying one.

I would be very happy if they brought out a Beeb edition of the Pi 400 with beige case, red function keys etc and a decent Beeb/Archie emulator on it.

[BigEd]

Does jsbeeb run reasonably well? It's a far cry from baremetal, but if it runs at full speed and in fullscreen mode, maybe that doesn't matter.

[scruss]

I find it bizarre there is no straightforward Beeb emulator on the rPi, given it's the spiritual successor.

It might have felt that way in 2012, but I haven't heard that sentiment in years. I don't think anyone at Raspberry Pi Ltd does, either.

I recently bought a Pi5 and it won't even run RISC OS now

Given that it was quite the fight to port the old Arch ABI to run on the first-gen Raspberry Pi, aarch64 is so far removed from that. 64-bit Linux flies on the Raspberry Pi 5. I wonder how many Arch emulators I could run at full speed on it?

BeebEm on the PC is perfect but I'd rather run it on a Pi, ...

b-em on the Raspberry Pi is remarkably good, and is not difficult to build. Here's how: Building on Linux · stardot/b-em Wiki
Although the instructions say it's for 32-bit Raspberry Pi OS, I've used them to build on 64-bit. It builds quite quickly, especially if you use 'make -j' to use all of the cores to compile it.

BeebEm was originally for Unix, but the Windows port didn't port the changes back to the original project. While you can run it on Linux, it doesn't spark joy, so you probably shouldn't.

If you want BBC BASIC V (sans assembler), Soruk's rather lovely Matrix Brandy BASIC is in the Debian repo. To install:

Code: Select all

sudo apt install brandy

It's not quite the current version (see every moan about Debian ever for details) but it's solid. It doesn't include the terminal-only emulators, but that will come after the next Debian refresh. A gotcha for new users: you can't run it as a background task (brandy &) despite it opening another window because it needs the original terminal window for the editor called up by the EDIT command. You'll likely curse the default Debian system text editor: I have no idea why Linux text editors are still so entirely minging.

I would be very happy if they brought out a Beeb edition of the Pi 400 with beige case, red function keys etc

The Raspberry Pi 400 is a very slow seller. During the chip shortage, when I was a Raspberry Pi reseller, we could sell any Raspberry Pi we could find the second it hit our website ... except for the 400. We had a box of 25 in stock that sat on the shelf the whole time. I think we sold three, but two were returned as "not being Raspberry Pis". The company probably still has a few of them.

The chance of there ever being a Raspberry Pi 400 in Acorn trade dress, containing someone else's IP as an OS, is none at all. Sorry.

As BigEd says, jsbeeb runs anywhere there's a browser. It does run at a decent clip on Firefox on a Raspberry Pi 5.

[tricky]

Does beebjit run on a pi?
It doesn't have much in the way of comforts but it's an excellent emulator.

Eben originally wanted beeb livery for the 400, but it was going to cost too much. There are several threads about making keyboards with beeb keys but they never work out very cheap.

[Duglor]

I am running a b-em emulator on raspberry pi 4.71 retropie from an trusted anonymous source.

I will attach the .sh here in a zip file here to this msg.

Place it in
/home/pi/RetroPie-Setup/scriptmodules/emulators
or place it in :
/home/pi/RetroPie-Setup/ext/RetroPie-Share/scriptmodules/emulators

when you run setup and experimental options...there then becomes an option to install it.
f11 brings up menu
ALT-ESC quits back to emulationstation.
The emulation works though keyboard only unless the game natively supports a joystick, then you can use a joypad. It's odd.

Folly, the author, wrote to me...
"I read that you are promoting my module-script on stardot.
That's ok but make sure you link to my repository.
Then everyone knows where the module-script originally came from and people can dig in to improve it.

Here are the b-em ones :
https://github.com/FollyMaddy/RetroPie- ... /emulators

the allergro4.sh is for the retropie raspberry pi. I am using quite old source code that works very good on the raspberry pi's."

[scruss]

Does beebjit run on a pi?
It doesn't have much in the way of comforts but it's an excellent emulator.

I could only get the headless build to compile on my Raspberry Pi 5. ClockSP gives an overall rating of 1024 MHz: I expected better. Console I/O over ssh is roughly Prestel speed. It posts similarly dismal numbers on my M2Pro Mac Mini: 1268.47MHz overall.

What has everyone here got against b-em? It's almost as if it has a bad smell every time I mention it.

[tricky]

b-em is great, but had already been suggested.
Personally, I only use an older windows version as Allegro 5 doesn't work at all well on my PC and anything using it runs very slowly! (4 was fine).
BeebEm was always the most user friendly, but also well behind b-em in emulation accuracy.
From what I have seen, they are both great now, jsbeeb and beebjit are also excellent..
beebjit has very few frills and so is likely to be more easily built for various linux distro's, I have never built for linux, so this is just my impression!