I last left my Acorn RiscPC with a StrongARM CPU card and an IBM/Cyrix based 5×86 CPU card. I saw something come up cheap on eBay which I decided to purchase just due to its uniqueness which changes things a little.

The StrongARM CPU card I used has a CPU made by DEC and was an original version of the Acorn StrongARM card. But later on the StrongARM technology was transferred to Intel, and later StrongARM cards used in Castle manufactured RiscPCs use these chips. I found one on eBay and purchased it.

OK, this card is a bit… “minging”. There is something crudding up all the metal parts of every component on the board. My best guess is a battery or capacitor leak from the machine it was originally in. That or mould from wherever it was stored.

So, I gave it an ultrasonic wash in Safewash Super, an ultrasonic rinse in deionised water and then dried it in my dehydrator oven. This cleaned up the board quite a bit:

Next up, those electrolytic capacitors. I was not sure whether or not they were good, but they have been physically abused, so I decided to replace them anyway. Afterwards I took a photo of it along with my original StrongARM card.

There are a few key differences you can see between the two:

• Obviously the CPU manufacturer.
• The model number and issue number to the right of the CPU.
• The clock speed of the crystal.
• There are no clock dip switches on the Intel card.

At this point I decided to plug it in and see if it works.

Success! It is a 236MHz card, which is a little slower than the 243MHz that my original overclocked card is currently running at. But if I solder on dip switches and cut the traces to unlock the clock speed it should be even more overclockable.

With that I can now say that my RiscPC has “Intel Inside”, and not in the x86 CPU card!