An Alternate-History Microcomputer Ecosystem
This public repository contains curated HomeComp project files, including emulator releases, documentation, ROM and cassette images, development tools, source code examples, old project material, and supporting artefacts.
The main emulator source code is not currently published here. This repository is the public archive and documentation front door for the wider HomeComp project.
To understand the project you need to understand a little about the author. Don’t worry, no complete biography, just the salient facts. I am a long-time retrocomputing enthusiast who started with computers in the late 1980s with a 16K Sinclair ZX Spectrum, then an Amstrad CPC464, Commodore Amigas and eventually Windows, Linux and macOS computers.
I grew up surrounded by the popular micros in the UK market including things like BBC Micros, Commodore 64s, and RM Nimbus PCs. I started with BASIC by copying magazine listings on my first computers but didn’t really learn to program until college where I picked up COBOL and Pascal.
Over the years I’ve dabbled with a few personal big projects. Most notably a PILOT interpreter for the Commodore Amiga in AMOS BASIC. A Simple Machine Emulator in Pascal for university. Conway’s Game of Life in Java and Intel 8008, 8080 and Space Invaders Emulators.
I’ve been studying the history of microcomputing and games consoles for a very long time and have amassed a sizeable collection of retro computing magazines in PDF format dating back to 1979.
The current public focus is HomeComp Ecosystem Era 1, beginning with the September 1977 HC-77B launch.
The first release wave is intentionally small: it introduces the HC-77B base machine, supporting documentation, early emulator material, and the foundations for later software and peripheral releases. Future updates will expand the public archive gradually as additional fictional products are released into the ecosystem.
Structured project documentation is available in the HomeComp Wiki.
The wiki covers emulator use, released machine specifications, HomeComp history, ecosystem release details, and the HC-77B expansion bus API.
This project was built and designed with significant assistance from ChatGPT, an AI large language model. The general responsibility split was as follows:
- HUMAN: Lead Designer, Project Manager, Tester, Researcher
- AI: Research Assistant, Design Consultant, Programmer
It is important to note the high level of documentation and planning required to properly focus and bound the code generation.
The Lore, or backstory, is central to this project and was developed over about a two week period with ChatGPT. The basic concept is built upon three rather unlikely events:
- I can time-travel back to 1975
- I am immortal or otherwise can appear as an 18 year old in 1975
- I know the winner of the Grand National or Football Pools
Given that far-fetched scenario, what would I have done differently? Could a fictional UK home micro company be guided through the pitfalls of the 1980s and 1990s into becoming a serious modern technology company? Could it survive where Acorn, Sinclair and Amstrad failed and avoid repeating mistakes of the Archimedes or Amiga?
The answer is, if you’re careful and unusually lucky (some may say prescient), yes. There probably was a route for a UK manufacturer to survive into the modern era and become a major technology company alongside the dominant American platform holders. A modern company would be focused on AI and wearable technologies.
In HomeComp terms an Ecosystem is a three-year period which contains a main computing platform the fictional company would have been primarily offering the consumer at that time, and all the surrounding hardware, software, firmware, books and peripherals that make that core product feel real and complete.
Era 1 covers the period from 1977 to 1980. This would have been the launch period and was dominated by single-board systems. Computers such as the Sinclair ZX80, Acorn System 1, Commodore KIM-1 and Nascom. The aim was a £100-200 system board that a fledgling home micro company could build upon. The result is a system inspired by machines such as the KIM-1, while not being compatible with them, and which gradually extends toward something closer to the Nascom-1 class of machine.
HomeComp is not an open-source project. The main emulator source code is not currently published in full.
Public HomeComp releases are made available in the public domain as giftware. They may be downloaded, used, copied, shared, and archived freely. Optional donations may be accepted through itch.io and Ko-fi, but payment is not required.
Some source material may be published where it is useful to the project, including CPU cores, monitor assembly listings, BASIC listings, example programs, SDK material, and third-party extension examples. The publication of selected source material does not make the overall project open source.
Where a specific source package or listing carries its own licence notice, that notice applies to that material.
Much of the HomeComp codebase and supporting material has been produced with AI assistance. The project does not intentionally include copied proprietary code, artwork, text, game assets, characters, or trademarks. Some software, interfaces, games, examples, and fictional products may be influenced by period hardware, common programming techniques, public-domain examples, historical systems, or familiar genre ideas.
If any material appears to infringe an existing copyright or trademark, please raise an issue so it can be reviewed and, if necessary, removed, replaced, rewritten, or relicensed.