[SiriusHardware]

Nice video about OSI - I can remember Ohio Scientific but never knew they'd offered such a basic trainer system.

Now all we need is something similar for Acorn computers, no doubt entitled 'From Little Acorns..' and starting with the System 1.

I spent a while looking around the Digirule stuff but one thing I could not see was whether it used the instruction set of an existing uP family or whether it has its own 'custom' instruction set. Did you manage to work that out? I see it's been fully backed, anyway.

From the logo on the main IC (Microchip?) I would say the underlying uP is a PIC.