{"id":28757334,"url":"https://github.com/libretro/81-libretro","last_synced_at":"2025-08-04T06:33:50.155Z","repository":{"id":42134264,"uuid":"38341582","full_name":"libretro/81-libretro","owner":"libretro","description":"A port of the EightyOne ZX81 Emulator to libretro","archived":false,"fork":false,"pushed_at":"2024-10-21T17:02:15.000Z","size":1543,"stargazers_count":20,"open_issues_count":6,"forks_count":33,"subscribers_count":9,"default_branch":"master","last_synced_at":"2025-06-17T03:11:43.437Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":null,"language":"C","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"gpl-3.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/libretro.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null}},"created_at":"2015-07-01T01:12:47.000Z","updated_at":"2024-10-21T17:02:21.000Z","dependencies_parsed_at":"2023-01-21T14:46:26.328Z","dependency_job_id":"c759f862-093b-4eb5-aaaa-8f9bd1b79b00","html_url":"https://github.com/libretro/81-libretro","commit_stats":{"total_commits":176,"total_committers":24,"mean_commits":7.333333333333333,"dds":0.375,"last_synced_commit":"340a51b250fb8fbf1a9e5d3ad3924044250064e0"},"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/libretro/81-libretro","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/libretro%2F81-libretro","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/libretro%2F81-libretro/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/libretro%2F81-libretro/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/libretro%2F81-libretro/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/libretro","download_url":"https://codeload.github.com/libretro/81-libretro/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/libretro%2F81-libretro/sbom","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":268658006,"owners_count":24285611,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","status":"online","status_checked_at":"2025-08-04T02:00:09.867Z","response_time":79,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2025-06-17T03:10:33.652Z","updated_at":"2025-08-04T06:33:50.051Z","avatar_url":"https://github.com/libretro.png","language":"C","funding_links":[],"categories":[],"sub_categories":[],"readme":"# 81-libretro\n\n**81-libretro** is an *work in progress* port of the [EightyOne](https://sourceforge.net/projects/eightyone-sinclair-emulator/) (a.k.a. THE Sinclair Emulator) to [libretro](http://www.libretro.com/). It's being developed on Windows with MinGW (64 bits) and Debian 8, and tested on RetroArch 1.2 frontend.\n\n## Games\n\nThe classic ZX81 games are all over the Internet, but check the [colorized](https://github.com/leiradel/81-libretro/tree/master/colorized) folder for games with Chroma 81 support. There are also many original games for the Zeddy, check [Bob's Stuff](https://bobs-stuff.itch.io/) for some high quality games. \n\n## Emulated Machines\n\nEightyOne emulates a number of ZX80, ZX81, clones, and other computers based on the same hardware:\n\n* Sinclair ZX80\n* Sinclair ZX81\n* Timex TS1000\n* Timex TS1500\n* Lambda 8300\n* Ringo R470\n* MicroDigital TK85\n* Jupiter ACE\n\nHowever, **81-libretro** only emulates the Sinclair ZX81 with 16Kb RAM for now. Other machines will be added as time permits. Push requests are welcome.\n\nThe port correctly loads and runs ~~some~~ many games I have around in the `p` format. `tzx` format is also supported.\n\nEightyOne also emulates some ZX Spectrum machines, but those were left out of this core on purpose. For a ZX Spectrum core for libretro, see the [Fuse core](https://github.com/libretro/fuse-libretro).\n\n## Core Options\n\nThe only core option available on the frontend is:\n\n* Tape Fast Load (enabled|disabled): Instantly loads files if enabled, or disabled it to see the moving horizontal lines while the game loads\n* 8K-16K Contents (ROM shadow|RAM|dK'tronics 4K Graphics ROM + 4K RAM): Selects the contents of memory addresses between 8192 and 16383, a shadow copy of the ROM, 8K of RAM, or [dK'tronics 4K ROM plus 4K of RAM](http://www.fruitcake.plus.com/Sinclair/ZX81/Chroma/ChromaInterface_Software_CharacterSetROM.htm)\n* Size Video Border (normal|small|none): Select the size of video border\n* High Resolution (auto|none|WRX): Enables WRX high resolution\n* Emulate Chroma 81 (auto|disabled|enabled): Enable the [Chroma 81](http://www.fruitcake.plus.com/Sinclair/ZX81/Chroma/ChromaInterface.htm) interface\n* Video Presets (clean|tv|noisy): Change how the video is emulated (if Chroma 81 is enabled, the video is set to \"clean\" regardless of this option)\n* Sound emulation (none|auto|Zon X-81): Enables sound emulation\n* Joypad button (up, down, left, right, a, b, x, y, l, r, l2, r2) mappings (auto|default|new line|shift|space|.|0|1|2|3|4|5|6|7|8|9|a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z): Maps a joypad button to a keyboard key, defaults are the cursor keys for the directional pad and '0' to all the other buttons\n* Transparent Keyboard Overlay (enabled|disabled): If the keyboard overlay is transparent or opaque\n* Time to Release Key in ms (500|1000|100|300): How many milliseconds to wait before releasing the key pressed using the keyboard overlay\n\n## Keyboard and Controllers\n\nA keyboard and a cursor joystick are configured and should work out-of-the-box.\n\n## Supported Formats\n\nThe `p` and the `tzx` formats are supported.\n\n## Save States\n\nSave states are supported, but the format is likely to change when more machines are emulated.\n\n## Setup\n\n1. Compile **81-libretro** with `make -f Makefile.libretro`\n1. Copy the resulting `81_libretro.dll` or `81_libretro.so` into the `cores` folder of your libretro frontend\n1. Profit!\n\n## Game Database\n\nSince configuring the core for each game can be a tedious task, **81-libretro** now features auto-configuration. Games support auto-configuration are listed in the `src/gamedb/gamedb.json` file, along with some information and the configuration required to play them.\n\nCurrently, there's no way to change the auto-configuration settings short of recompiling the core after making the changes. If you feel the provided auto-configuration could be better or has bugs, please open an issue and I'll take a look.\n\nThe core comes with auto-configuration for all homebrew games from [Bob's Stuff](http://www.bobs-stuff.co.uk/zx81.html), and some of the games available at [Paul Farrow's collection of colorized games](http://www.fruitcake.plus.com/Sinclair/ZX81/Chroma/ChromaInterface_Software_Colourised.htm) (namely the ones available for download here in the `colorized` subfolder). If you want to add auto-configuration for a missing game, please submit a push request with changes only to the `gamedb.json` file.\n\n## Thanks\n\nErik Olofsen for help with:\n\n* The correct values to set the Z80 registers and some memory variables to successfully load `p` files\n* Chroma 81 emulation\n* `tzx` support\n* Zon X-81 sound emulation\n\nSee also the `colorized` subfolder.\n\n## Versions\n\nVersions that are being used to build and test **81-libretro**:\n\n* EightyOne version 1.0 (test a)\n\n## TODO\n\nSee the open issues.\n\n## Bugs\n\nMany, probably. Open issues or send push requests.\n\n## License\n\nGNU GPLv3.0\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flibretro%2F81-libretro","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Flibretro%2F81-libretro","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Flibretro%2F81-libretro/lists"}