Question about ArcEM Archemedies Emulator on Raspberry Pi 3

Hello again. I was able to install RISC OS on my new Raspberry PI 3, but I’m unable to get !ArcEM to work. It sort of runs, but at the same time, it doesn’t. When I run the program without any rom images, it displays a grey screen stating it needs a rom image or something like that. However, if I run !ArcEM with a rom image then the program closes out. I looked at the user manual and found something that stated: ‘If the emulator can’t find a suitable screen mode, it will quit.’

I would like to get !ArcEM to run, but I have some questions. First, is it a screen issue or a issue with the software possibly not being compatible with the Raspberry PI 3? My screen resolution is at 1920×1080. Secondly, if it is a screen issue, how do I change the programs screen resolution so it doesn’t close out (if it is the programs screen resolution causing problems and not the system)? Finally, have you got ArcEM to work, and how did you manage to get ArcEM to run on your system?

Thanks for your time,

Grhmhome.

I have had ArcEm running (in part to test the CLib changes) on a Pi1, though I don’t recall if I needed to do anything specific. It might be an idea to try AnyMode?

I note however that you are using a Pi3 and ArcEm is built using GCC. There are some underlying issues that need fixing, such as the SWP instruction no longer exists. I’m not sure whether or not this is the cause of your problem, but the differences in the Pi3’s ARMv8 should be kept in mind.

I have ArcEm on my Pi 1 and I don’t recall having to use AnyMode. I’m away from both my Pi 1 and 3 for a few days though so can’t do any further testing.

I don’t like to have this kind of off topic answer, but you should try archiemu too. It’s faster and can work in windowed mode :)

http://www.tellima.nl/riscos/

This is an ugly hack to get Arcem running on Pi3.
Using an editor like !Zap you could load in the ‘arcem’ file (inside !Arcem) dated Dec 18, 2015 and replace the three SWP’s with loads and stores.
The SWP’s are at &46170, &461E4 and &55378. Otherwise F7, search for SWP.
You might want to change 11 instructions:

&46180 ADD R0,R0,#&40, MOV R2,#1, SWP R1,R2,[R0]
change to:
MOV R2,#1, LDR R1,[R0,#&40], STR R2,[R0,#&40]!

&461DC ADD R0,R3,#&40, MOV R1,#1, SWP R2,R1,[R0], CMP R2,#0, STRNE R2,[R0]
change to:
MOV R1,#1, LDR R2,[R3,#&40], STR R1,[R3,#&40], CMP R2,#0, STRNE R2,[R3,#&40]

&55370 MOV R1,#0, ADD R2,R3,#&28, SWP R1,R1,[R2]
change to:
MOV R2,#1, LDR R1,[R3,#&28], STR R2,[R3,#&28]

I have no idea what this hack does but at least !Arcem starts up for me, ymmv. I will let Arcem run for a couple of hours on a demo, see how stable it is.

Sorry, mistake, address 55370 has ‘MOV R1,#1’ originally, of course.

Thanks, jan de bore. I’ll give it a try asap. The reason I want ArcEM to work is so I can play games.

I got it to work. I edited address 55370 and it runs.

Can somebody please provide a link to a patched ‘arcem’ file please?
As I’m not familiar using !Zap to change SWP’s.

Can somebody please provide a link to a patched ‘arcem’ file please?

A recompiled version is available here. It’s built with the RPi 3 compatible version of UnixLib.

Thanks for the recompiled version Chris.

Speaking of RISCOS ArcEm – does anyone know what keycodes its expecting an the commandline to redefine the keys. I’ve tried various codes from the PRM’s and none of them seem to work.

Speaking of RISCOS ArcEm – does anyone know what keycodes its expecting an the commandline to redefine the keys. I’ve tried various codes from the PRM’s and none of them seem to work.

Low-level internal key numbers (it is mentioned in the manual, although it looks like there are a couple of typos in the HTML version)

Remember that you need to press both keys at the same time to open the tweak menu. If you only want it to respond to one key you can cheat and specify the same code twice.