What is it?
RISC OS is a computer operating system used in the old Acorn 32 bit range, Castle's Iyonix computer, Microdigital's Omega and Mico machines as well as the RiscStation RS7500.
What set's RISC OS apart from just about every other operating system under the sun is easy to see and easier to understand - it's size and speed.
RISC OS comes on two chips. Yep, you heard me right there. Two chips totalling 4Mb of OS. As the OS is on a chip, the machine doesn't need a hard drive, it's immune totally to any nasty which attacks the OS (though a virus can attack any modules on the hard drive) and because of the lack of clutter and very tight coding, it's damned fast!
Other than that, the chips also include the full desktop environment and everything else you could need, including some small (but useful) applications.
RISC OS hardware
Of course, the OS is nothing without the hardware
Originally, Acorn (a smallish company in Cambridge, UK) created a thirty two bit processor for their range of machines. They did this from the ground up. Yep, a small company designed and created another company (ARM) to fabricate the chips. They then wrote the OS. Other than in the UK, where on earth would you find something like that!
RISC OS was not the first OS for these processors, that "honour" goes to ARTHUR (there was a joke that it was called that as they wanted A Risc machine by THURsday). ARTHUR, while rather nice, was buggy and could cause problems for the user. It was also only a single tasking OS
ARTHUR was quickly supersceded by RISC OS 2. This was more like it! A proper multi-tasking operating system, still on ROM but it was good. It was also only something like 1988. So while the world was playing with 16 bit Amiga's and Atari machines, plus some really dodgy PC boxes, in the UK we had a full 32 bit OS with 32 processors, a full desktop environment (other than on a Mac, that was unheard of!) and stability.
After RISC OS 2, came 3.0. 3.0 was like DOS 4. Evil, buggy and rather unpleasant. This was sorted out with OS 3.1. Software for OS 2 would not work with OS 3.1 without messing about. That was fine and to be expected.
3.1 was used for a good while and then the RiscPC came on the scene. This was the first box to have OS 3.5 in it. It was here Acorn made their biggest mistake in my opinion - they included such a high level of backward compatibility that it meant people didn't have to upgrade in order to use the new software. From that moment on, they were doomed.
OS 3.6 came out to take advantage of the ARM710 with OS 3.7 for the StrongARM and 3.71 the ARM7500FE. Acorn never made another released to the public version of the OS and quietly died (it was sold to different companies effectively) in 1997.
Enter RISCOS Ltd
Peter was an ex-Acorn employee before the fall. He was asked to see if there was a way to buy, via a consortium of companies (from memory) what was left of the doomed Pheobe project. A good idea. Except for one thing - Peter Bondar. At one meeting (which companies paid around £ 500 to attend, mainly to pay for Peter), he described Acorn computer users as being in one of two camps - the anoraks and education. Really not what you would want to hear!
After the failure of a number of projects (include Peter Bondar's efforts - to which all I can say is thank goodness!), a company was formed which successfully bought what was RISC OS 3.8 from the remains of Acorn (now Element 17) and set about fixing it for release as OS 4...
Lots of work later, OS 4 was released to the big bad world in 1998. Boy was it lovely. Faster, more efficient and with far fewer bugs. Sure the CDROM support wasn't amazing and it was still not a threaded OS, but hey, it was movement.
Around that time (well, upto a year later), RiscStation brought out their very nice RS7500 machine which was based around the ARM7500FE (the same as the Acorn A7000FE had under it's hood. For quite a lot of the time, it shifted faster than the SA RiscPC could. The machine had far better sound capabilities than a lot of PC hardware had, networking as standard, the ability to take Zip drives without additional software
Microdigital also brought forth their ARM7500FE machine, the Mico. To be honest, it was nowhere near as good as the RS7500 machine - parts of it still don't work as they should!
The problem...
While both the RS7500 and Mico were miles better than most of the other RISC OS hardware, why did they not sell like hot cakes? The simple reason was historic. Acorn's mentality
The beauty of Acorn machines is that they never break down and due to the decisions made when the company brought out OS 3.5, people still using their old kit could still use all of the software being produced, so why should they bother upgrading? This and one other mistake had started to cost the RISC OS market dearly
The second mistake harked back to the original RISC processors. While it is true that they were 32 bit processors, they only had 26 bits available, the others were used for flags. As time went on ARM became a company in it's own right. It carried on making chips, but now it was not just for Acorn machines, but the world as a whole. They soon ditched the 26 bit models to go full 32 bit, with the upshot that other than the ARM7500FE chips, very few processors would have dual 26/32 bit addressing systems. This included the StrongARM.
With the lack of purchases, hardware projects (such as the RiscStation Evolution and their laptop) soon became less viable until in the end, not much was happening
Enter Castle
Castle were to change this with the launch of their XScale Iyonix machine. It had a completely new version of RISC OS (OS 5) and would not listen to anything 26 bit without the support of a piece of software in the middle. The OS was the version Pace had been using and developing before they closed down their operations
Now the Iyonix represents a very large jump in the RISC OS market - far larger than the movement to OS 4 or the move to the StrongARM in the RPC. It is completely new and well supported. The only problem is the cost.
It is way too high. For the same cost of an Iyonix you can build a 3GHz+ PC with more stuff on it that you will ever need, DVDRW support as standard, lots of hardware extras and basically the machine you could ever want
It means that a machine will do only one thing at one time