ARM development systems
Dave Holden
This article began when I decided to try to find out what development boards with ARM processors were available. In this context 'ARM' means a RISC processor which uses the normal ARM instruction set that is used for RISC OS, so processors designed or manufactured by other companies such as Intel, Samsung, etc. would be included. The main idea was to discover how much hardware already existed in the 'real world', who was actually producing it and whether any of it could be suitable for use with RISC OS.
I was also interested in what devices were already available using ARM processors where RISC OS might be used.
Note that in neither case was I particularly concerned with the practicality of actually getting RISC OS to run on any of these devices. I was only concerned with whether there was any potential opportunity for promoting RISC OS as an operating system on them and whether this could open up any new niche markets.
Where are they used?
It soon became obvious that ARM processors are used almost exclusively in embedded systems and portable handheld devices. Here their low power consumption, low cost and ease of programming give them an advantage over CISC devices such as the Intel xx86 range.
We are probably all aware that ARM processors are widely used in things like laser printers, network devices and mobile phones. However, there's not much of a market opportunity for RISC OS in this type of device. One of the great strengths of RISC OS is its user interface and WIMP, and this isn't really suitable for very small screens. Even if it were possible to get RISC OS running on some of these devices there would be little point in doing so as the normal user interface for them is a series of text menus, which is much more practicable with such small screens.
The older type of small PDA, such as those pioneered by Psion, has now almost vanished as their functionality (and much more) has been absorbed into mobile phones. However, there are quite a few larger handheld devices with bigger screens where RISC OS might be used to advantage.
Moving up slightly in size we come to what are normally referred to as sub-notebooks. This looks more interesting. Their screens are large enough for the RISC OS WIMP to work reasonably well and they normally have processors with enough power to enable it to run at usable speed. However, because they are normally regarded by users as a 'small computer' people expect them to operate smoothly and seamlessly as a portable extension of their desktop computer. That would be fine if their desktop computer was also running RISC OS, but since it's far more likely to be using Windows or Mac OS we're back to the old problem of compatibility. Yes, there is potential in this area, but it would require a lot of work to persuade customers that they should pay the inevitable premium for running a 'foreign' operating system when the standard version of these machines will already come with most of the software they would normally need.
Development systems
Having had a (very) brief look at where ARM processors are used in consumer devices we now come to development systems. These systems allow a developer to test basic functionality and algorithms before committing to the design and building of an actual prototype. Many of them are also intended to be used in actual production systems where the numbers involved are too small to make it worthwhile to produce a dedicated board. This is extremely interesting, because it indicates where the industry itself expects the processors to be used. By looking at the systems that are offered, and the numbers of them in use for development it is possible to get some idea of the type of devices that companies are working on.
I'm not going to give a whole list of web sites and describe dozens of devices, you could easily find them for yourself. However, a good starting point is the UK site Direct Insight. Here you will find a number of development boards and other software and hardware tools, plus links to many other suppliers in the same field.
An example of what is available is the ADI Engineering 80200EVB. This uses the Intel 80200 733 Mhz XScale processor on a small board with various I/O and on board FPGA SDRAM and 4Mb of flash RAM, and all for around £400.
The ADI section of this site also shows the Tungsten development board, which is essentially Castle's Iyonix mother board. Unfortunately I couldn't find any prices and when I went to the actual ADI web site I couldn't find any mention of it.
Another useful site is Innovate Solutions. They show a number of interesting devices including the Tungsten board but the link to the datasheet appears to be broken and, once again, no prices.
One very interesting device shown is the Accelent Devkit from Vibren Technology which uses a 400 Mhz Intel PXA255 XScale processor. This is intended as a development board for small handheld devices and comes with a variety of I/O ports and a 7.7 inch full colour VGA LCD touch screen and a keyboard. The info for this says
"The Accelent DevkitIDP can be used to develop personal assistants (PDA), wireless web pads, set-top boxes, Internet audio and video devices, kiosks, point-of-sale (POS) products, hand-held devices and a wide variety of vertical market devices."
This is a very useful looking kit. It's the only one I've found where I got the feeling that if RISC OS were running on it there ought to be a niche market somewhere for it. The data sheet was available as a PDF file so I have included this in the Software directory for this issue.
Cogent Computer Systems are another company that supplies a number of development boards for ARM 7, ARM 9 and X-Scale processors. They specialise in small boards for embedded systems, one of which is the CSB226 which also has a 400 Mhz PXA255 X-Scale. There are all the usual input/output facilities and it also has an on board 800 x 600 LCD controller and, like the Accelent DevkitIDP, has facilities for direct connection to a 640 x 480 colour TFT touch screen. Prices for these boards are around £500, and others start at less than £150 one off.
Conclusions
It seems that no-one is contemplating using ARM processors for the sort of devices which would equate to a modern desktop computer. This is partly because even the fastest and most powerful processors just can't compete in raw power with the Intel and AMD processors designed specifically for that purpose. However, it has to be said that the people like Intel, Samsung, etc. that make ARM processors have almost certainly realised that the main strengths of this type of architecture doesn't lie in this area. The real market for these chips, and it's a huge market, is for the type of portable device already described, and here low cost and low power consumption are more important than processing 'grunt'.
There is a potential market for RISC OS in this area, but probably not for the sort of RISC OS we are familiar with. These devices would require a lot of 'under the bonnet' work to produce a new and more modular RISC OS. Acorn foresaw this many years ago with their Galileo project, but this never really got off the ground and now that there are so many other small, lean operating systems designed especially for this field and Unix derivatives ready to step in where a more 'computer like' system is required I wonder if it's going to be too late for RISC OS to compete.
Dave Holden