Acorn StrongARM Risc PC

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Introduction

In September 1996 Acorn launched the StrongARM RiscPC. The StrongARM RiscPC is similar to the RiscPC 700, but has a 202MHz StrongARM CPU and RISC OS 3.70. The main differences between the models were increasing memory, larger hard discs and, optionally, CD_ROM drives. The models include:

• SRP05 - 8MB, 2MB VRAM, 1GB hard disc
• SRP06 - 8MB, 2MB VRAM, 1GB hard disc, CD-ROM x 8
• SRP10 - 4MB, 1.2GB hard disc
• SRP11 - 4MB, 1.2GB hard disc, CD-ROM x8
• SRP15 - 8MB, 2MB VRAM, 1.2GB hard disc
• SRP16 - 8MB, 2MB VRAM, 1.2GB hard disc, CD-ROM x8

Later Acorn produced StrongARM Risc PCs with 233MHz StrongARM CPU . Once again models differed in memory and hard disc sizes and, optionally, CD-ROM drives. The models include:

• SRP20 - 233MHz, 4MB, 1.2GB hard disc
• SRP20A - 233MHz, 4MB, 1.7GB hard disc
• SRP21 - 233MHz, 4MB, 1,2GB hard disc, CD-ROM x 8
• SRP26 - 233MHz, ??

I have a StrongARM Risc PC (SRP26)  with a CPU Card with a 160MHz CPU overclocked to 202MHz. I think I have seen another example in the past. I don't know if it was a shortage of 202/233MHz StrongARM CPUs or Acorn saving money which resulted in use of overclocked CPUs but I don't think I have seen this in any Acorn Catalogue or Price List.

Documents and manuals

See Risc PC Computers  for general Risc PC documents.

StrongARM RiscPC

SRP26 (no 1)

Here is an SRP26 233MHz StrongARM RiscPC. It has an Acorn 233MHz StrongARM CPU, CJE Micros AMD5x86 PC Card and an i-cubed EtherLan 600 combo network card installed. It has a single case slice and an Acorn 2 way backplane. It runs RISC OS 3.70. I bought this computer on ebay in August 2009.
 
Here are some pictures:

 Acorn (SRP26) StrongARM Risc PC 

The StrongARM Risc PC is shown with an Acorn AKF60 monitor, running RISC OS 3.70.

 Acorn (SRP26) StrongARM Risc PC (front) 

The front of the StrongARM Risc PC shows the CD-ROM drive on the left and the floppy disc drive on the right. Like many Risc PC's the spring holding the front flap up has broken.

 Acorn (SRP26) StrongARM Risc PC (right)

 Acorn (SRP26) StrongARM Risc PC (back) 

The back of the StrongARM Risc PC showing, from left to right:

• The power sockets on the left. The bottom one is power in and the top on is power out for a monitor,
• The blanking plats for the 2 unused podule slots,
• The reset button,
• Audio out for a headphone or connection to an external system,
• The VGA monitor socket,
• The keyboard socket, a Risc PC can use any PS\2 keyboard,
• The BNC and RJ45 sockets on the i³ network card,
• The parallel printer port,
• The RS232 serial port.

The serial number (80-SRP26-1170062) is above the printer port.

 Acorn (SRP26) StrongARM Risc PC (top)

 Acorn (SRP26) StrongARM Risc PC with top cover removed 

Removing the top of the StrongARM Risc PC showing, from left to right:

• The CJE AMD 5x86 PC card in the top left with power cable for its cooling fan,
• The Acorn 233MHz StrongARM CPU card below it,
• The Sony CDU311 8 x CD-ROM drive at the bottom left,
• The i³ EtherLan 602 card is just visible in the middle top,
• The grey cable connecting the CD-ROM audio output to the motherboard,
• The VRAM is on the left above the battery,
• The RAM is below the VRAM,
• The Acorn 2 slot backplane is immediately above the floppy disc drive,
• The Sony MPF920-H floppy disc drive is at the bottom with the missing spring taped to it,
• The 103W power supply is on the left.

 Acorn (SRP26) StrongARM Risc PC with CPUs and backplane removed 

Removing the CPU cards exposes the RISC OS 3.70 ROM in the top left and the RAM modules in the middle right.

 Acorn (SRP26) StrongARM Risc PC with CDROM and Floppy drive removed 

Removing the case slice and the CD-ROM and floppy disc drive exposes:

• The Seagate ST31276 1.2 GB Hard Disc at the left front,
• The i³ EtherLan 600 network card at the top middle.

 Acorn (SRP26) StrongARM RiscPC motherboard

The StrongARM Risc PC motherboard is an issue 3 board (part number 1208,000) with 16 bit sound. It shows:

• The IDE socket for the hard disc and CD-ROM at the bottom left,
• The floppy disc socket above it,
• The square IOMD21 memory controller is above the floppy disc socket,
• The two CPU connectors above the IOMD21, normally the front connector is used for the ARM CPU and the back one for an optional x86 PC Card,
• The two RISC OS 3.70 ROMs are above the CPU connectors,
• The square SMC FDC37C665GT on the left provides I/O support,
• In the middle is the connector for a network card,
• The square VIDC20 is to the right,
• The VRAM module is immediately below the VIDC21.
• The RAM modules are below the VRAM. The top module is a 16MB DIMM and the bottom one the original 8MB SIMM,
• The battery for CMOS RAM, right, is showing signs of corrosion and needs replacing,
• The socket for the backplane is below the RAM,
• The 103W power supply is on the right.

Here is a HiRes picture of the Acorn SRP26 StrongARM RiscPC motherboard .

SRP26 (No 2)

This SRP26 StrongARM Risc PC is unusual because the CPU is a 160 MHz StrongARM  clocked at 200MHz. It also has an IFEL 16/32MB RAM Upgrade  and an i³ combo EtherLan 600 Network card . It has a single case slice and an Acorn 2 way backplane.
 
Here are some pictures:

Acorn (SRP26) StrongARM Risc PC 

This StrongARM Risc PC has been upgraded and is running RISC OS 4.02.

Acorn (SRP26) StrongARM Risc PC (front) 

Unlike many Risc PCs, the spring is still there and keeps the front flap up. Note the flap says Risc PC and not Risc PC 600 or Risc PC 700.

 Acorn (SRP26) StrongARM Risc PC (back)

The back of the StrongARM Risc PC showing, from left to right:

• The power sockets on the left. The bottom one is power in and the top on is power out for a monitor,
• The blanking plats for the 2 unused podule slots,
• The reset button,
• Audio out for a headphone or connection to an external system,
• The VGA monitor socket,
• The keyboard socket, a Risc PC can use any PS/2 keyboard,
• The BNC and RJ45 sockets on the i³ network card,
• The parallel printer port,
• The RS232 serial port.

The serial number (80-SRP26-1170775) is above the printer port.

Acorn (SRP26) StrongARM Risc PC with top removed 

Theis picture shows the StrongARM CPU card above the CD-ROM drive, part of the i³ network card in the middle of the back, the back plane above the floppy disc drive and the 103W power supply on the right.

 Acorn (SRP26) StrongARM RiscPC with CDROM and floppy drive removed

With the case slice, CD-ROM, floppy disc, backplane and CPU card removed, you can see the ribbon cables that connect the CD-ROM and hard disc drive to the IDE socket and the floppy disc drive to the floppy disc socket on the motherboard. You can also see the power cables.

The most notable point in the picture is that the battery has been removed from its location on the right of the motherboard next to the power supply, in it place is a socketted rechargeable AAA battery has been wired to the motherboard. The battery is at the front of the case below the power cables.

Acorn (SRP26) StrongARM Risc PC with cables removed 

With the ribbon cables removed you can see:

• The 1.2GB Seagate ST31276 hard disc drive at the bottom left,
• The i³ network card in the middle at the back,
• The 1MB VRAM below and to the right of the network card,
• The 2 x 32MB memory modles below the VRAM.
• The replacement battery at the middle front with the orange B&Q label.

Acorn (SRP26) StrongARM Risc PC motherboard 

The motherbard is an issue 3 board (part number 1208,000) with 16 bit sound. It shows:

• The IDE socket for the hard disc and CD-ROM at the bottom left,
• The floppy disc socket above it,
• The square IOMD21 memory controller is above the floppy disc socket,
• The two CPU connectors above the IOMD21, normally the front connector is used for the StrongARM CPU,
• The two white labelled RISC OS 4.02 ROMs are above the CPU connectors,
• The square SMC FDC37C665GT on the left provides I/O support,
• In the middle is the connector for a network card,
• The square VIDC20 is to the right,
• The socket for the VRAM module is immediately below the VIDC21.
• The sockets for the RAM modules are below the VRAM,
• The battery for CMOS RAM, to the right of the RAM socket, has been removed and replaced with a rechargeable AAA battery,
• The socket for the backplane is below the RAM sockets,

Here is a HiRes picture of the Acorn (SRP26) StrongARM Risc PC motherboard .

Specifications: