The uMSX is a MSX2+ FPGA implementation that basically mimics the 1ChipMSX (one of the first FPGA based MSX2+ one chip MSX computers commercially available).

The VHDL used is the well known KDL PLD implementation for the MSX2+ used by the vast majority of the FPGA based MSX computers known. The uMSX uses the first generation of the KDL VHDL source, also known by esemsx.

Based on the already obsolete (but relatively easy to find) Altera EP1C12 FPGA (specifically the EP1C12Q240C8N), the uMSX uses SMD based components (and a few PTH) in a nice compact form factor. It uses the 4 megabit EPCS4 active serial configuration flash memory to host the firmware and configure the FPGA chip at each time the circuit turns on.

A MT48LC16M16A2 SRAM chip offers memory for the computer, which also uses a few other components to implement the clock logic (NC7WV04P6X inverter and 21.47727 basic PTH crystal oscillator) and a 953B voltage detector and reset IC.

Heavily based on 0603 SMT resistance arrays, and other 0805 SMT components, the uMSX is a compact little OCM MSX that can be used to evolve your SMD soldering skills, challenge your knowledge of modern electronics applied to retro computing, and give you a lot of fun through the journey.

• Article I wrote with additional information and instructions to build the project: https://theretrohacker.com/2022/07/08/yet-another-fpga-based-msx-the-umsx/
• Github repository with additional resources: cristianoag/uMSX: Files to build, program and test the uMSX FPGA MSX2+ clone (github.com)