RPCEmu - macOS

I’m a macOS user using version macOS Big Sur Version 11.0.1

Which is the best version of RPCEmu to download, and what other files will be needed, RISC OS boot drive, hard drive, rims etc, and where can these downloaded from.

What folders need to be created in your main PRCEmu folder.

Thank you

What follows is a synthesis of the methods I used to get RPCEmu running on macOS Catalina. While it isn’t guaranteed to work on macOS Big Sur, it should at least point you in the right direction.

• Go to https://www.riscosopen.org/content/downloads/riscpc and download the IOMD 5.28 stable softload archive (IOMD-Soft-5.28.zip).

• Go to https://www.riscosopen.org/content/downloads/common and download the self-extracting version of the stable RISC OS 5.28 disc image (HardDisc4.5.28.util).

• Download RPCEmu itself. This is available from https://github.com/Septercius/rpcemu-dev/releases – I suggest you download the latest Release version (at the time of writing this is RPCEmu-0.9.3a-Release.zip).

• Unpack the archive and copy the two apps (RPCEmu-Interpreter and RPCEmu-Recompiler) to an “RPCEmu” folder under “Applications”.

• Create a new “shared RPCEMU data” folder under your own user (e.g. in “Documents”). I suggest you call the folder “RO528-RPCEmuData”. Copy the contents of the “Data” folder from your RPCEmu distribution archive (Your “RO528-RPCEmuData” folder should now contain cmos.ram, COPYING, hostfs, netroms, poduleroms, readme.txt, roms and rpc.cfg).

• Open the RO528-RPCEmuData folder and go to the “roms” folder. This should contain exactly one file (roms.txt) although it doesn’t matter if that file is missing. If there are any other files present in the “roms” folder, delete them.

• Find the RISC OS ROM in the IOMD download (it’s the file called “riscos” in soft/!Boot/Choices/Boot/Predesk/!!Softload). Copy the “riscos” file into the “roms” folder inside RO528-RPCEmuData: I suggest you give the file a meaningful name such as “riscos528”.

• Go back to the RO528-RPCEmuData folder. If it contains a file called “hd4.hdf”, delete it. You only need do this once (RPCEmu will create an empty file the next time it is run – for RISC OS 5 you just need to be sure the file really is empty).

• Copy the “Harddisc4.5.28.util” file to the “hostfs” folder inside RO528-RPCEmuData.

• Start RPCEmu-Recompiler. At this point macOS will complain that the app has come from an unknown developer – you will have to jump through the necessary hoops to get it to run (e.g. on macOS Catalina you can control-click on the app icon, then choose “Open” from the menu, then double-click on the app).¹

• As this is the first time RPCEmu-Recompiler has been run, it will ask you for the location of the data directory. Point it at “RO528-RPCEmuData”.

• You may need to adjust some of the RPCEmu “Preferences” from the RPCEmu menu. I suggest:
  • StrongARM emulation
  • 64MB or 128MB RAM
  • 2MB or 8MB VRAM
  • Three-button mouse

• RISC OS should start up, but will complain that !Boot is missing. Go to the desktop by entering the command
  *Desktop
  You may get another prompt that the system boot did not complete properly, but you will eventually get to the desktop itself. Do NOT select “Reboot” at this point!

• From the RISC OS desktop, click on the “HostFS” icon in the bottom left of the screen. This will open a directory viewer containing one file: “HardDisc4/5/28/util”.

• Click MENU (middle mouse button, or Command-click) on “HardDisc4/5/28/util” and hover on the arrow to the right of “File ‘HardDisc4/5/28/util’” on the menu. This will open a “File” submenu. Hover on the arrow to the right of “Set type” and enter Utility into the dialogue box. Press Return to complete the action. The file icon for “HardDisc4/5/28/util” should change to “Utility”.

• Double-click on “HardDisc4/5/28/util”. This will unpack its contents into a directory called “HardDisc4”.

• Double-click on “HardDisc4” and drag the !Boot directory into the root directory of HostFS (i.e. alongside “HardDisc4” and “HardDisc4/5/28/util”).

• Press F12 to drop to the command line and enter the following two lines:
  Configure FileSystem HostFS
Configure Boot
  Press Return again to re-enter the desktop.

• Press Ctrl-Shift-F12 to shut down RISC OS, then click on the “Restart” button that appears. RPCEmu may give an error – if that happens, just start up RPCEmu again.

• This second load of RISC OS should proceed all the way to the desktop without any errors. You can now copy the other directories (Apps, Utilities etc.) from the HardDisc4 directory to the root directory.

• RISC OS will have started up with a default (640×480) screen display. Double-click on !Boot and select “Screen” from the Configuration window that appears.

• On the Screen configuration window, click the “menu” button to the right of the “Monitor type” field and choose “Other > Generic”. Repeat this process for the “Resolution” and “Colours” fields (to choose 1024×768 pixels and 256 colours). Click on the “Set” button at the bottom of the window to finish.

• The system is now ready for use.

¹ If you want to use RPCEmu-Interpreter as well, repeat this process. Note that RPCEmu-Interpreter and RPCEmu-Recompiler can point at different Data directories if you want.

Stuart,

Thank you for your posting, I will try your step by step guide and see how far I get, or if I’m able to get RPCEmu up and running.

Thank you.

Stuart,

I get to the following, which I will call step 11. “As this is the first time RPCEmu-Recompiler has been run, it will ask you for the location of the data directory. Point it at “RO528-RPCEmuData”.”

What happens at this point is, I get the following message from RPCEmu, “ROM Image of unsupported size: expecting 2MB, 4MB, 6MB or 8MB, got 11471 bytes.”

I then click the OK button and then RPCEmu shuts down.

Step 12, You may need to adjust some of the RPCEmu “Preferences” from the RPCEmu menu. I suggest:
StrongARM emulation
64MB or 128MB RAM
2MB or 8MB VRAM
Three-button mouse

If I start RPCEmu again and get the error message again I’m unable to change any settings as you have suggested in step 12 because the menu is grey out and unable to select anything, or change any settings.

Looking at the rest of the RPCEmu menu, everything is grey.

What can I now do to correct this, or is it an error that I may have made.

Thank you.

Mark Stephens has an article in the latest Archive magazine which describes a much simpler method, only 5 steps!

I don’t know MacOS, but it looks like he does steps 3+4 from above (downloading and decompressing RPCEmu) then downloads one of the easystart bundles from here http://www.marutan.net/rpcemu/easystart.html and uses that to populate your Data directory. This has the added benefit of giving you a nice bundle of software pre-installed to get you started.

ROM Image of unsupported size: expecting 2MB, 4MB, 6MB or 8MB, got 11471 bytes

By the looks of things, you copied the file “Softload” into the “roms” folder – you should have copied the file “riscos” (step 7). Delete all the files in the “roms” folder and copy the file “riscos” into the folder. You can then continue from step 12.

While it isn’t guaranteed to work on macOS Big Sur, …

Thanks Stuart – It is now running on my mac mini M1 Big Sur 11.2.1
complete with cries of “unclean” from the OS and a whinge about allowing dangerous stuff to enter the holy temple of ’Tosh it went exactly as you describe.

I have just looked at the RPCEmu website for info on networking. There is documentation for Windows and Linux but nothing I can find for Mac.

Hi Stuart,

I have finally managed to now go through all of the 23 steps. Because I don’t have a 3 button mouse at the moment, when I move the mouse button over any icon or folder, and if I press the Command key (cmd) this will bring up the RISC OS menu.

I have now rebooted a number of times, no issues on re-booting at all, the default screen size is 800 × 600, but what I would like to do is set the default screen size to 1024 × 768. The 2 other screen modes 1280 × 480 and 1600 × 600 just don’t look right, so 1024 × 768 looks the best option.

I have not yet tested the CD ROM drive or the Floppy Drive.

Is it possible to open .ADF file formats.

Now when RPCEmu boots up and click on HostFS, I can now see the following !Boot, Apps, Diversions, Documents, Printing, Public and Utilities folders.

Yes thank you again Stuart, your guide is very helpful and very useful.

My next step is to see if I can get The BBC Emulator up and running.

Is it possible to open .ADF file formats.

Yes. In RISC OS, go to the Configuration utility (e.g. double-click on !Boot) and select “Discs”. Increase the number of floppy discs to 1 and click on Set. Now go to the RPCEmu “Disc” menu (at the top of the Mac screen) and choose “Floppy > Load Drive 0”. After selecting your ADF file you can click on the floppy disc icon to open it.

Be aware that most .ADF files contain programs that assume you are running an older version of RISC OS, so may not work all that well on RISC OS 5.

If you want RPCEmu to emulate an older version of RISC OS, go to http://www.marutan.net/rpcemu/easystart.html and download the RISC OS 3.71 “Other platforms” edition. This contains a replacement Data directory ready to be swapped in to your RPCEmu installation.

what I would like to do is set the default screen size to 1024 × 768

In the Configuration utility, select “Screen” and choose the desired resolution. Now click on “Set”.

Looks like I’m now fully up and running.

Type *FX0 then shows RISC OS 5.28 (19 Oct 2020) which what I would expect.

Post deleted – no longer needed.