Sol-1 is a homebrew CPU and Minicomputer constructed using 74HC logic. It boasts impressive hardware features, including user and kernel privilege modes, paged virtual memory, multiple ports, a real-time clock, and more. The CPU also includes unique elements such as prioritized external interrupts, a microcoded sequencer with 15 ROMS, and fast indexed string instructions akin to x86’s REP MOVSB and others. The register table includes general purpose and special purpose registers for various functions. The software side is equally robust, with a Unix-like operating system, assembler, full C compiler, SystemVerilog model, and an emulator. The author also plans to bring several text-adventure games to Sol-1 in the future.
http://www.sol-1.org/index.php