Exciting times - the StrongARM Risc PC and the A7000+ (1996 to 1997).

At 11:12am on Tuesday 26th March 1996 the first StrongARM Risc PC processor card prototype was powered up. It used a clock speed of 228 MHz and managed a benchmark of 290,000 Dhrystones under RISC OS. This got quite a lot of people rather excited.

The StrongARM chip was a joint venture between Acorn and Digital. In a departure from the design of the standard ARM chip, the StrongARM used the Harvard Architecture. In this architecture, there are two Level 1 caches, one for instructions and one for data. For the StrongARM both caches were 16 Kb in size. The chip also operated a 5 stage pipeline. Coupled with the increase in clock speed to 200+ MHz (compared to 40 MHz for an ARM 710) this resulted in a considerable speed increase, even in some unexpected areas - network access times were quicker, and it took 10% to 15% less time to format a floppy disc!

The next major development in the StrongARM story was the release of the StrongARM on a daughter board, as an upgrade for the Risc PC. The chip as shipped (a model SA110 StrongARM) was clocked at a shade over 200 MHz (202.4 MHz, according to Acorn User). BASIC code executed 10 to 20 times faster, and one piece of specially created assembler code was 35 times faster! What was even more impressive was that the entire StrongARM daughter board consumed approximately 1 Watt of power.0

The release of the StrongARM card required an update to RISC OS, to version 3.70. This version, which was backward compatible with the earlier ARM chips, featured a rewritten kernel and various other enhancements.

The StrongARM upgrade card and a copy of RISC OS 3.70 cost about £250, ex VAT. StrongARM-based Risc PC's, with 1.2 Gb hard drives and 4 Mb of memory or 10 Mb of memory (8 Mb main memory, 2 Mb VRAM) cost from £1149 and £1399 respectively.

In mid 1997 an upgraded A7000, the A7000+, was released. This featured an upgraded processor, the ARM 7500FE, clocked at 48 MHz and with an integrated floating point chip. The motherboard now had two SIMM sockets, one filled with 8 Mb by default, and the memory was clocked at 32 MHz, twice the speed of the Risc PC. The case was identical to the A7000 and was still limited in its expansion capabilities.

The A7000+ was supplied with a 1.2 Gb hard drive and cost about £900 or £1000 if a CD-ROM drive was supplied with it.

Acorn had three more announcements in 1997. The first was an upgraded StrongARM Risc PC. The StrongARM's clock was upgraded from 202 MHz to 233 MHz. I've also found a reference to a J233, a StrongARM Risc PC with extra software installed, such as Java and Browse.

The second announcement was the Acorn NetStation. This was intended to be a Home Network Computer (NC). The NC was based around the ARM 7500FE, clocked at 40 Mhz, with 8 Mb of memory (upgradable to 32 Mb). The only storage device was a SmartCard. The OS was supplied in ROM.

Two versions of the NetStation were released. One had a 33,600 bps modem and the second had an Ethernet interface. The box was supplied with a 15-pin monitor output, composite video output, sound output, PS/2 mouse and keyboard sockets and a parallel interface, which could be connected to a printer or a Zip drive (drivers for the Zip drive were provided in ROM).

The NetStation was very similar internally to the A7000+, and most RISC OS applications would run on it. The provided web brower was called NC Browser and was based on Fresco (as supplied with the ANT Suite). Several other pieces of software were supplied in ROM, such as NC Writer (based on EasyWriter). It was also possible to use a Risc PC to provide the remote filing system resources (mainly bootp and NFS) o support the EtherNet version of the NetStation. This required running a version of UNIX (such as RiscBSD) on the Risc PC (because the NetStation looked for a bootp server on boot-up).

The third announcment, made towards the end of 1997, was the Acorn CoNCord, a second generation NC. The stying of the tower-style case was described by Acorn User as "supersonic". The CoNCord was powered by a StrongARM SA110, clocked at 233 MHz. It came with 4 Mb of memory (expandable to 256 Mb) and 2 Mb of VRAM. It featured a Smartcard interface and could support both PAL and NTSC. Java support was built in.

Towards the end of 1997 everything was looking relatively rosy. Acorn had good products in a variety of markets. The NC technology was used by a number of big players, including Oracle and SGI, and ARM chips were being licenced left, right and center. Who would have thought that by the end of 1998 the Acorn world would be reeling from a succession of major shocks and the dream would be in tatters?

Next: The end of the dream - Phoebe (1998).


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Robert McMordie

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