RISC World

MicroDigital Omega Press Day

Aaron Timbrell was there....

On the 18th of July, at the Victoria Hotel in Bradford MicroDigital held the official press launch of the new Omega computer. Both David Atkins and Dave Prosser from MicroDigital were present along with myself, Dave Holden from APDL, Paul Beverley from Archive, Paul Middleton from RISC OS Ltd, Richard Hallas from Foundation RISC User and a host of other specially invited guests. One strange omission was a representative of Tau Press, publishers of Acorn User, no sign of Steve Turnbull or of Rob Donaldson, the elusive new Acorn User Editor.

The meeting kicked off with David Atkins explaining his "Spectrum" development program. Despite what you might think this has nothing to do with old Sinclair computers but to do with the proposed MicroDigital product range. The "Spectrum" ranges from yellow at the bottom, through green, to blue at the top. The Omega is the green machine in the middle of the range.

David Atkins from MicroDigital

The MicroDigital "Spectrum"

David Atkins then spent some time explaining the differences between the proposed machines. Firstly the yellow machine, this is basically a cut down Omega with a slightly cut down spec as follows:

  • 300Mhz SA110 processor
  • DDR 266Mhz RAM
  • 32 bit data bus
  • 100 Mbit ethernet
  • 2 USB interfaces
  • ATA 100 hard disc interface
  • Single chip lightning graphics

The proposed machine would also come with 2 serial ports, but no PCI expansion slots or Parallel, keyboard or PS2 interfaces. Although this board could power a desktop computer, using a USB keyboard and mouse, this isn't what Microdigital have designed it for. Instead the board is aimed at computer control applications. David was able to demonstrate a prototype control simulation application designed for schools. My personal view is that the board isn't really aimed at schools, but at the more lucrative commercial computer control markets. RISC OS would be ideal for this as it starts very quickly and doesn't need a potentially fragile hard disc to store programs.

David Atkins then went on to describe the top of the colour spectrum, the blue machine. This has a spec above that of the current Omega:

  • Dual SA110 and XScale processors
  • 64Bit data bus
  • Super high resolution Lightning Graphics
  • ArmTwister technology
  • ATA 133 hard disc interface
  • PCI V 2.3 Expansion
  • 1 Million gate Xilinx Virtex 2 FPGA

This board has apparently already been designed for a Japanese company that produces medical devices. David Atkins explained that one of the board's first jobs would be to assemble 3D images from 2D slice scans produced by medical scanners. He was also able to confirm that RISC OS would be used as the OS of choice.

The Omega

Why is the Omega "Late"

David then moved onto to the reason we had really trekked all the way up to Bradford, the Omega. The first question related to why the Omega had been announced at RISC OS 2000, but still hasn't shipped yet. The answer was simple; getting the large FPGA (Field Programmable Gate Array) chips to perform to their published specification. The FPGA chips are the heart of the Omega, as they allow RISC OS to think it's seeing VIDC20 and MEMC chips, as found in the current generations of RISC OS machines. The FPGA chips allow massively increased performance, but look just like Acorn's chip designs to RISC OS. Another advantage of FPGA chips is that they can be reprogrammed easily, even by the customer! Most of the Omega chipset can be reprogrammed with the exception of the SA110, XScale and Southbridge chip. This means that a user of an Omega could simply download a program from the MicroDigital website, which would re-program the hardware and speed up the performance of the computer. For example it is quite likely that the first batch of Omegas will ship without the Lightning Graphics hardware acceleration enabled, the hardware will be on the motherboard, but it won't be activated. Once the drivers have been completed a user will be able to just download the firmware update, run it, and hey presto the hardware acceleration will be turned on. For those that think this sounds a bit fanciful let me assure you it isn't. I recently had to upgrade the firmware in our home DVD player. I simply went to the manufacturers website ( and downloaded a zip file. Then all I had to do was decompress this and write the files to a CD using the PC. Once you pop this writable CD into the DVD player it ran the upgrade program, asked to be restarted and was updated with a new title screen, new menu options and improved DVD playback, all for free!

So what is the Omega like?

The first question must be is it stable? The answer is yes. An Omega was used for all the presentations throughout the talk given by David Atkins and it didn't show the slightest sign of instability. The prototype on display was in the finished case design, but lacked some of the drivers for the floppy and CD-ROM drives. Also the prototype machine had to be "kick started" from a PC in order to get it to start loading RISC OS. David Atkins did say that all production Omegas would be coming with a free PC to start them up. Then had to explain that this was a joke to a couple of those present. All production machines will come with RISC OS on ROM and will turn on the same as any other RISC OS machine.

Once started the normal RISC OS desktop appeared, the whole presentation was done in 1024 x 768 pixels (the maximum resolution of the projector) with 24 bit colour at 80Hz, although the Lighting chip was shown going as high as 1600 x 1200 in 24 bit colour at 75Hz. A wide range of RISC OS software was demonstrated during the talk, including Artworks, Impression Publisher, Easiwriter, TEK 1608 and Vantage. All seem to run very well on the new machine. A few quick speed demos were tried using Draw. Having re-created these on my 287 Mhz StrongARM machine I think the Omega, even with hardware acceleration switched off, still feels 3 times the speed of my old RISC PC.

A bad photo of the Omega desktop

The Omega will be shipping with a software bundle consisting of DrawWorks, Ovation and a number of other packages. I was also able to have a quick chat with a couple of developers who are working on Omega specific versions of some of their products, but I can't spill the beans at this point, and I am not allowed to publish the screen shots I have either.

The X-Scale and ArmTwister

The first Omegas will come with the SA110 soldered to the motherboard and a socket for the X-Scale add-on card. This will be available later at a projected price of around £149. Having installed the X-Scale processor a user would then have to run the program to enable the ArmTwister technology that allows both processors to work at the same time. Simply put ArmTwister allows the X-Scale, which is a 32bit only processor, to run a 26 bit operating system (such as current versions of RISC OS) and 26 bit applications with the help of the SA110. David Atkins would not be drawn on how ArmTwister works but one can make a semi educated guess. My assumption, which may be wrong, is that as each block of instructions is fetched into the processors cache it is examined for 26 bit only instructions. If the block does not contain any it is shunted into the X-Scales instruction cache. If it does contain 26 bit code then it is shunted into the SA110 processor cache. Since the SA110 can run both 26 and 32 bit code it does not matter if there is a mixture of 26 and 32 bit code in the same block. This would have a massive advantage over current machines. As more and more code gets converted to 32 bit, more and more will be running on the X-Scale, and the Omega will get faster and faster. Some quick "back of a fag packet calculation" indicated that in a couple of years time an Omega could be running 3 to 4 times its current speed, having only had an X-Scale and some downloads from the website added. So if my impressions are correct and the Omega is already 3 times faster than a RISC PC, in a couple of years it could be 12 times faster!

Looks Like ArmTwister to me!

The Omega benefits from a number of other improvements; the hard disc interface will be capable of running at over 40 Mb a second, it can handle over 1 Gb of RAM, it can have a proper PC card added and can take advantage of lost of cheap PCI expansion cards once the drivers have been completed. MicroDigital are already working on drivers for Sound cards, Ethernet cards and SCSI. The Omega also has USB interfaces that are compatible with those designed by Simtec.

So when is it coming?

Soon. Not a good answer but the only one we could get, David Atkins would not be drawn on a release date. However he was able to say that the hardware was finalised, and it was purely down the the length of time it would take to complete the remaining drivers. However I have now seen and used an Omega and I am convinced. In my opinion it is the best RISC OS machine ever designed. It's fast, small and, considering the prices of the "alternatives", cheap. Not only that but its easy to expand it, the flexible design means that its design can be "upgraded" just by downloading and running a bit of software. At RISC World we like it a great deal, and judging by the response from others in the room so does everyone else. Indeed I cannot think that I have ever seen Paul Middleton from RISC OS Ltd look so happy. He can see the future of desktop RISC OS computers, and so can I.

Aaron Timbrell