RISC World

RISC OS in a PC World

Dave Holden introduces the great debate...

There has been great debate in recent months over the merits of both RISC OS hardware and the VirtualAcorn emulation route. Since there has been so much discussion about it we thought it would be a good idea to pitch both side of the argument. We aren't saying that either argument is correct, or indeed incorrect. We have asked two RISC World contributors with different viewpoints to put their points and Aaron isn't going to edit either one (beyond spelling and grammer - ED).(see my editorial on opinions - ED) but he will not let that influence any part of this. However before we see both points of view I think it would be wise to review a little of the history of PCs and Acorns.

The past...

From the very early days Acorn always tried to run other operating systems on their hardware. Even the BBC computer had 'add on' second processors which enabled it to run CPM and DOS. In fact it was actually designed with them in mind.

When the Archimedes was launched Acorn appreciated that a significant proportion of users also needed to use DOS. They therefore produced the PC Emulator, which was nearly as fast as the 'industry standard' 4.99 MHz PC XT of the time. Later the ARM 3 gave this a speed boost but it had fallen behind in both speed and the model of the hardware it emulated, although it was still a useful tool as many businesses were still running DOS software (Lotus, Wordperfect, etc.) on something like a 12 Mhz PC AT.

There were, of course, also the machines intended to run a version of UNIX. As these were really intended for specialist use I'll not go into details here, but it's worth remembering that there usually was (and is still) a UNIX-like alternative to run on the hardware.

As PC performance increased Acorn and Aleph 1 worked together to supply a hardware solution, and various PC cards were produced. Most of these were 'podules', but some were designed to be fitted to the A3000, A3010, A3020 and A4000 machines. The problem with all of these was that they were extremely expensive, which is hardly surprising as they were, in effect, a complete PC on a card. So much so that they were often dearer than a PC system of equivalent power. They were also limited in performance, both in terms of processing power and RAM, since they couldn't share RAM with the host processor and, particularly with some models of computer, the amount of power that could be supplied to an expansion card was limited.

By the time the RiscPC appeared Acorn were aware that something better was needed now that Windows (at that time 3.1) was rapidly becoming the norm. A major selling point of the new machines was therefore the PC card. At 33 Mhz it was capable of running most of the contemporary Windows and DOS software at usable speed, and at just £99 the price was right.

So up until this time RISC OS users who also needed to run DOS or Windows as a second OS could do so without too much cost and at a reasonable speed. From this point on, however, things were not so rosy.

Desktop PCs began to take off in a big way. By now they had 'escaped' from the office, and were finding their way into more and more homes. Prices were falling, and, with newer and faster processors, performance was rapidly increasing. In the space of a few years the 'standard' PC went from something like a 33 Mhz 386 to a 330 Mhz PII, and, now that the machines were being used more and more in the home rather than just for business, there were corresponding increments in graphics and sound capabilities.

Meanwhile we got the Strong ARM, with its big performance improvement on the RISC OS side, but the ability to run Windows on a RiscPC (by now DOS was effectively obsolete) was becoming more expensive.

After the original PC card there was a 66 Mhz 486, then a 100 Mhz 486. These were quite a bit quicker than the original, and then 100 Mhz and 133Mhz 586 cards followed and were even better for Windows. For a short time the RiscPC's performance was snapping at the heels of a basic budget PC, but not for long, and there were other problems.

The biggest problem was cost. The original 33 Mhz PC card was a complete package. For your £99 + VAT you got the card, the software to run it, and a copy of DOS. Because DOS was neither memory hungry nor required large hard discs, that was pretty much all you needed. Once Windows became the PC standard, particularly Windows 95 and later, things changed. Firstly the faster cards were quite a bit more expensive, rising to over £250 for a 586. Secondly the standard software wasn't good enough if you wanted to run Windows. Aleph 1 produced much improved software which did allow PC card users to run later versions of Windows reasonably well, but it added more cost, another £70 or so. At this time most RiscPC owners were happy with 16 or 32 Mb of RAM and something like a 400 Mb hard drive. It was possible to use Windows 3.1 with 16 Mb of RAM allocated to the PC card and a few hundred Mb of hard drive space, but with Windows 95 this wasn't anything like enough. By the time users had added enough RAM and a bigger hard drive (and these things weren't always as cheap as they are today), and purchased a copy of Windows it was costing more to add a PC card to a RiscPC than to buy a complete stand alone PC system, often well over £500.

There were some advantages in having both systems in a single box, but it wasn't long before PC performance was leaving the PC cards way behind, not the least because of the 32 Mb RAM limit, and this was happening while PC prices continued to drop. By the end of the 90's the RiscPC PC card was no longer a viable alternative to a real PC for any serious user.

The present...

This is pretty much where we were until recently. If you needed to use a PC, and more and more people did, then if you wanted to use RISC OS you really needed two computers. This wasn't as bad as it sounds, because the RiscPC and PC could share a monitor and keyboard, and these are the components that take up most space. Also low PC prices meant that cost wasn't a major factor.

This was made even more attractive by the fact that there wasn't any new RISC OS hardware, so most users weren't forced to make a choice between spending money on a new PC or a new RISC OS machine. They could continue running their RISC OS software and still have an up to date PC, or as up to date as they felt they needed, without any penalty. Another 'pro' is that now that so few RISC OS computers are used in schools the release of these machines onto the secondhand market meant a dramatic drop in the cost of a secondhand NIC card, which makes networking a RiscPC and PC much cheaper.

Now the situation has changed, there is new RISC OS hardware, there are the Iyonix and the Omega. There is also VirtualRPC-SE, which allows users to run RISC OS 4 and RISC OS Select on PC hardware. It's time to make a choice. Do you choose the hardware route, or do you choose the emulation route? It depends on what your priorities are. The next two articles in this feature are designed to put the case for using VirtualAcorn and the case for using a real RISC OS computer.

Dave Holden