The KIM-1 (Keyboard Input Monitor) was a 6502-based single-board computer produced by MOS Technology in the 1970's. It had 1152 bytes of RAM and a 2K byte ROM containing a simple monitor program for entering programs in the form of hexa-decimal numbers using a hex keypad. Output was displayed on a six-digit seven-segment display.
The KIM Uno is a pocket calculator-sized replica of the KIM-1. It uses an Arduino Pro Mini to emulate the 6502 processor and memory, and a simple PCB to connect it to the KIM-1-style hex keypad and 8-digit (!) seven-segment display. It provides the original KIM-1 ROM, 1152 bytes of RAM and 1024 bytes of nonvolatile RAM.
The KIM Uno usually comes as a kit, but I got mine pre-assembled. It also normally comes without a case, but mine had a well-made 3D-printed ABS case. However, it was basically just a box containing the Uno and a 9V battery, and you still had to operate the Uno by pressing micro switches on a PCB with hard-to-read markings next to the switches. So my first project was to make a new case.