Cove — 16-bit Fantasy Console
A complete 16-bit computer system built from scratch. CPU, assembler, graphics, audio, debugger — all in Rust. Problem I wanted to build something that touches every layer of a real system: CPU architecture, assembly language design, graphics, audio, memory mapping, interrupts, debugging tools. Constraints are what breed creativity. When modern games ship at 80+ GiB, there’s something refreshing about stepping back and working with only 64 KiB. Approach I designed a custom instruction set architecture (ISA) with mixed 16/32-bit encoding, 8 general-purpose registers, deterministic cycle timing, memory-mapped I/O, and interrupt handling. The system is split into three independent crates: core (CPU, memory, 21 syscalls), assembler (multi-pass with labels, forward references, and automatic short-to-long expansion), and emulator (SDL2 with REPL debugger, breakpoints, disassembly, and basic backtrace). ...