Microprocessors are most often used in applications where firmware and increasingly high levels of software are available. It’s very rare for someone to interact directly with a microprocessor, and it’s a painful process if you try. Instead, you work with the microprocessor through a series of abstraction layers that are much more friendly to human brains. But, if you want the experience of direct interaction, Agilemaxi’s KIM Uno is a microprocessor dev kit emulator you can build yourself.
The KIM Uno was inspired by the MOS Technology KIM-1, which was created by Chuck Peddle and released in 1976. MOS Technology’s first microprocessor, the 6501, was designed to be used with existing motherboards built around the Motorola 6800. But, Motorola wasn’t too happy with that idea, so they sued. In response, MOS Technology created the very similar 6502, but it wasn’t compatible with Motorola 6800 motherboards. So, they needed a machine for user to interact with the 6502, which is where the KIM-1 came in.
The KIM-1 allowed users to run assembly language programs on the the 6502, and Agilemaxi’s KIM Uno fills the same role by emulating retro processors on an ATmega328P — the same microcontroller used in many Arduino boards. To build one yourself, you’ll first need to get the custom-designed PCBs made. Other than that, you’ll only need a few components: the ATmega328P, tactile push buttons, seven segments displays, and a few other miscellaneous discrete components. Assembly is straightforward, but you’re going to need some serious programming chops to actually use the KIM Uno.