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The KIM Uno is a portable, software defined dev kit for (retro) microprocessors. But let me introduce the idea of it by going back in time:

Back in late 2018 it came to my mind, that I wanted to build a small portable microprocessor dev kit, just like the famous KIM-1 from MOS Technology, Inc. and designed by Chuck Peddle who was also involved in creating the 6502 CPU.

But building a “bare-bone” dev kit with discrete logic components was no option since it needed a big power supply (since those ancient devices tend to take some serious current) and also the development would be very time intensive. And I want it now!

Therefore, I designed the KIM Uno as a portable device, which fits in one hand and is powered by two CR2032 batteries. It uses the ATMega328p (“Arduino”) microcontroller running at 8 MHz to emulate (or simulate) a desired CPU. This architecture also makes sure, that the emulated CPUs are interchangeable to anything which fits inside the microcontroller’s flash memory. So it is a multi-purpose device.

By coincidence I later watched a really good talk - called The Ultimate Apollo Guidance Computer Talk (34C3) - on YouTube where “One Instruction Set Computers” or OISCs are mentioned. I did not know about them and found this as the perfect candidate to implement it.

The KIM Uno emulates a CPU with just one instruction: subleq - subtract and branch if less than or equal to zero.

If you follow along with me through this Instructable, you can build your own KIM Uno in no time. And the best part - beside the fact that you can modify it to your taste - is, that it only costs 4,75 € to make (as of end 2018).

One hint: there is a Git repository which contains all the files provided by the different steps of this instructable. In case you want to modify some resources and share them with us all you can make a PR. But you can also download all files at once there. Simply to to Thanks!”

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