DIRT-16 #

DIRT-16 (Dynamic Instruction and Register Toolkit - 16 bit) is a 16-bit fantasy computer for recreational computing and retro-inspired game development. It uses the LOAM (Logic Operations And Mechanics) ISA, which has been designed for this project.

The backend, machine and frontend are rust crates: the backend implements the LOAM CPU (pure processor, memory goes through a Bus trait), the machine crate is the DIRT-16 computer itself (RAM, devices, the bus between CPU and chipset), and the frontend is the interactive shell (screen, input, cartridges). The programs in ./toolchain are (at least intended to eventually be) programs that run on the DIRT-16 itself.

The spec is designed to be emulated as opposed to run on hardware, though part of the design philosophy is that nothing should be out of the blue for a prospective FPGA implementation.

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Project Goals #

• 16-bit CPU, 24-bit address space
• 32MHz CPU clock
• Emulator that runs on binaries
• Provides OS with file system and shell
• Provides assembler and compiler for developing on the OS
• Capable of graphics and sound (rudimentary 3d software rendering if possible)
• Frontend that emulates screen and data cartridge interface

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Todo List #

• Clear specification of LOAM ISA (LOAM_spec.md)
• Clear specification of DIRT-16 computer (DIRT-16_spec.md)
• Implement backend (LOAM CPU emulation library)
• Implement machine (DIRT-16 devices + bus, headless)
• Implement frontend (Displays framebuffer, manages keyboard/mouse, loads/ejects cartridges
• Write LOAM assembler (DAHLIA / DIRT16 Advanced High Level Instruction Assembler)
• Make test binaries (Currently just a simple GCD algorithm and graphics tests)
• Write language spec + compiler (ACANTHUS, strongly typed rust/lisp-like systems language)
• Write OS (LILIES / Lightweight Interrupt Layer and I/O Executive Subsystem)