# jdah/jdh-8

An 8-bit minicomputer with a fully custom architecture

Repository: https://github.com/jdah/jdh-8
Canonical: https://ross.abutalabs.com/products/jdh-8
Language: C
License: MIT
License Family: permissive
Last push: 2022-06-05T13:59:09+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 1953, "days_push": 1550, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1382, forks 96 (observed 2026-08-28T04:04:34.379385+00:00)

## What it is
JDH-8 is a fully custom 8-bit minicomputer with its own RISC instruction set, register set, and port-mapped I/O, complete with an assembler and SDL2-based emulator. It also includes a Logisim Evolution schematic documenting the hardware design.

## Use cases
- emulate a custom 8-bit computer
- write assembly programs for a simple RISC architecture
- learn how computers work at the hardware level
- run retro games like Pong on a homemade machine
- study CPU design with a full schematic
- build a toy computer from scratch

## When to choose
- you want a self-contained educational 8-bit computer with emulator and assembler
- you want to experiment with a simple custom ISA in C
- you want a complete hardware schematic alongside the software toolchain

## When to avoid
- you need a production or performant emulator for real hardware
- you want a well-documented, beginner-friendly SDK with extensive docs
- you need modern 16/32/64-bit or ARM emulation

## Facets
- artifact type: application
- maturity: maintenance
- function: interpreter, compiler, simulation, developer-tools
- domain: hardware, simulation, education, developer-tools, programming-languages
- platform: windows, cpp, cli
- tags: 8-bit-computer, emulator, assembler, retro-computing, custom-architecture, sdl2, logisim, linux, macos

## Member repositories
- jdah/jdh-8 (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:34.379385+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:40:07.475682+00:00, confidence not recorded.
  - readme: https://github.com/jdah/jdh-8 (fetched 2026-08-28T04:04:34.379385+00:00, sha 1d2c4fb4b4d9)
- Data as of 2026-08-30T08:39:29.467469+00:00.