Emulator User Manual
This page explains how to run the released HomeComp emulator as a modern application.
It is not the HC-77B machine user manual. The fictional HC-77B manual is included separately in PDF form with the emulator release and explains the front-panel monitor, address entry, data entry, register display, program execution, and cassette operations.
Release files are stored in the main HomeComp repository.
The current public release covers the HomeComp's HC-77B Single Board Computer.
September 1977 saw the release of the HC-77B system itself along with optional expansion hardware to connect a Teletype (TTY) device, Keyboard, and television display controller.
In November 1977 a 3K RAM Expansion was released, giving a total 4K user space. The RAM expansion was bundled with a free cassette game, NIM.
Easter 1978 brought the first two major cassette software releases: an Advanced Monitor Tools cassette giving command-line access to the system ROM, a text editor, and a 6502 assembler; and HC Cassette BASIC.
Mid 1978 adds the HC Scrolling LED Display: a 32×8, single-colour red LED peripheral and a base-machine demonstration cassette. The display appears through the emulator's Devices menu when its extension is installed.
September 1978 adds the HC-77B 8K ROM BASIC configuration. The ROM BASIC release provides a resident programming environment for TTY and Keyboard/CRT systems and includes compatibility import for earlier HC Cassette BASIC programs.
Easter 1979 introduces the HC-77B Complete System Bundle, bringing the mature 4K RAM, Keyboard/CRT and ROM BASIC configuration together as a complete system.
Late 1979 adds the HC-77B Text & Printer Pack. The expansion provides a 40-column virtual impact printer together with the resident Text Editor and printer ROM. The printer appears through the emulator's Devices menu and supports persistent virtual paper, manual paper feed, PDF export, host printing and clearing of printed output.
The emulator is currently released for:
| Platform | Build |
|---|---|
| Windows | win-x64 |
| macOS | macOS-x64 |
| macOS Apple Silicon | macOS-arm64 |
| Linux | Linux |
The emulator executable/application name depends on platform:
| Platform | Application |
|---|---|
| Windows | HC-77B.exe |
| macOS | HC-77B Emulator.app |
| Linux | HC-77B |
The emulator release uses the following folder structure:
config/
docs/
extensions/
roms/
tapes/
Stores emulator configuration files.
This folder is used for host-side emulator settings rather than fictional HC-77B machine files.
Contains included documentation.
This is where the HC-77B machine manual and other public documentation files are expected to live.
Contains released emulator extensions and peripheral examples.
Contains ROM files used by the emulator.
The HC-77B boot ROM is included with the release.
Contains cassette image files used by the emulator.
Run:
HC-77B.exe
Open:
HC-77B Emulator.app
On macOS, the first launch may be blocked because the app is not notarised. Open System Settings → Privacy & Security, find the message about HC-77B Emulator.app, then choose Open Anyway.
If macOS blocks the app even after using Open Anyway, remove the quarantine attribute from Terminal:
xattr -dr com.apple.quarantine "HC-77B Emulator.app"Run:
HC-77B
If the file is not executable, set executable permission from a terminal:
chmod +x HC-77BThen launch it again.
The emulator provides three main menus:
System
Devices
About
The emulator System menu provides the main power and application controls.
The System menu provides Power On and Power Off controls for starting and stopping the emulated hardware, plus Exit to quit the application.
The Devices menu is used to access attached or available emulator devices.
Devices may include built-in emulator windows, released peripherals, or future extension-provided hardware. The exact contents of this menu depend on the current release package and installed extensions.
The About menu provides emulator and project information.
The HC-77B is a front-panel-first 6502 microcomputer.
Machine-level operation is explained in the included HC-77B User Manual PDF. Use that manual for:
- switching on the fictional machine
- understanding the front-panel display
- using the hexadecimal keypad
- entering addresses
- entering data
- inspecting memory
- viewing registers
- starting programs with
GO - using cassette
LOADandSAVE - following worked example programs
The emulator presents the machine. The included manual explains how to operate that machine.
The HC-77B boot ROM is included with the emulator release.
Users do not need to supply a separate boot ROM for the September 1977 launch release.
Cassette images belong in:
tapes/
Extension files belong in:
extensions/
The expansion and peripheral API is documented separately in the Expansion Bus API section of this wiki.
Check that you are using the correct build for your platform:
| Platform | Expected file |
|---|---|
| Windows | HC-77B.exe |
| macOS | HC-77B Emulator.app |
| Linux | HC-77B |
Also check that the release folder has not been partially extracted or rearranged.
Make sure the emulator has executable permission:
chmod +x HC-77BThen run it again.
macOS may warn about downloaded applications that are not distributed through the App Store.
Use the normal macOS security process for opening a trusted downloaded app.
Check that the release folders are still present:
config/
docs/
extensions/
roms/
tapes/
The boot ROM is included with the release, but the emulator still expects its normal folder structure to be present.
If a downloaded file opens as text beginning with something like:
version https://git-lfs.github.com/spec/v1
then the Git LFS pointer was downloaded instead of the actual file.
Use GitHub’s proper download controls or clone the repository with Git LFS support enabled.
This page describes the emulator user-facing behaviour for the September 1977 HC-77B public release.
The wiki will expand as later HomeComp ecosystem releases add new machines, software, cassette media, peripherals, and emulator features.