It is the early to mid 90s and you just forked out for an Acorn Archimedes or RiscPC machine, which was arguably a superior choice over PCs at the time. But you have some old DOS software you want to run. What do you do? It turns out that there were a few ways of solving this.

Possible solutions

There are four main options I’m aware of depending on your hardware. These are:

• Acorn’s PCEm emulator software
• FasterPC emulator software
• A PC second processor for RiscPCs
• A PC processor podule

I only have three of these to test, unfortunately I do not have a PC processor podule. It is on my wishlist but I haven’t found one at a good price just yet.

Acorn PCEm

PCEm is as the name suggests, a PC emulator for the Acorn Archimedes. It emulates an 80186 CPU with an FPU and can provide MDA, CGA and EGA graphics. It came in two versions:

• Single tasking CGA only
• CGA/EGA/VGA Multitasking

The version that came with my Archimedes A3010 happens to have both versions on one disk. Apart from supported video modes, the main difference is that the “multitasking” version lets you run RISC OS applications at the same time as the emulator is running. Single tasking is useful if performance is required, so that is what I’ll be using today.

FasterPC

This is a project created by Dave Lawrence and released in 1995 when he found himself unsatisfied with the performance of Acorn’s PCEm. It became available on the Risc World Volume 3 CD which is where I have obtained it from. This is actually one of the reasons I bought the Cumara CDROM drive, the installation comes with a 10MB hard drive file already pre-configured with DOS installed. It would have been a pain to transfer that using floppy disks.

FasterPC emulates an 80186 or it can be downgraded to an 8086 if needed. It also supports CGA, EGA and VGA graphics.

RiscPC second processor

RiscPC computers had two CPU slots inside them. The first used by the ARM CPU that drives the machine, the second can be used by a PC co-processor to run Windows and DOS applications somewhat natively. The catches being that RAM is shared with the ARM CPU and the ARM CPU is emulating things like the graphics and sound devices.

These CPU cards came in many flavours, typically based on the 486 generation of CPUs. Mine is a Cyrix/IBM 5×86 which I think is clocked at around 100MHz.

Benchmarks

To benchmark the various setups I used Landmark Speed Test 6.0 and Norton Sysinfo 6.0. I wanted to use Topbench but I could not make this run on PCEm or FasterPC.

The benchmarks were run on my Acorn A3010 which has 4MB RAM and an IDE podule and my RiscPC 700 which has a StrongARM 233MHz CPU as well as the PC co-processor. The RiscPC has 32MB of RAM and 2MB of VRAM.

A3010 PCEm

PCEm was showing as the equivalent of a 3MHz AT on Speed Test and Sysinfo did not know what to make of it at all. The CPU speed was bouncing around from around 1.1x to 2.1x and the clock speed was showing as around the 50MHz mark.

I tried running Alley Cat on this machine and it ran slowly with awful sound.

A3010 FasterPC

I was expecting FasterPC to benchmark faster, but it reported slower in both tools. That being said, when running Alley Cat on this emulator it ran significantly faster and with correct audio. Pretty much as if I was running it on my 8088 (NEC V20) based Schneider EuroPC.

RiscPC PCEm

Next up I attempted to run PCEm on my RiscPC. You could say it is showing as a little bit faster. Both benchmarking tools were confused by it, with numbers jumping all over the place. But either way I appear to have an 80186 that is way faster than designed.

RiscPC FasterPC

Just as with the A3010, the benchmarking of FasterPC was much more stable than PCEm, even if the results were “weird”. Speed Test says FasterPC is faster, Sysinfo shows a different story.

It would be cool to see an 80188 running at 1GHz as this suggests, but I’m pretty sure that is something only possible in the realm of FPGAs.

RiscPC PC card

Finally I ran the tests on my PC card. I don’t think these tests were really designed for a 586 to use. I’m also not sure why Sysinfo has gui issues with shadows.

Conclusion

If you want to run your old DOS PC spreadsheet or wordprocessor on your Acorn Archimedes, then any of these solutions would have been great. If you were more into 8086 DOS gaming then FasterPC is a great choice. But if you really want speed then you should look into a RiscPC PC card. I use mine for 486-era DOS gaming and I even have Sound Blaster support!