Skip to content

Late 1977 RAM Expansion and NIM

tmcd35 edited this page Jun 2, 2026 · 1 revision

Late 1977 — 3K RAM Expansion and NIM Cassette

The late-1977 release is the second public HomeComp release wave.

It introduces the official HC-77B 3K RAM Expansion and bundles it with a free NIM game cassette.

Release Contents

Category Released Material
Hardware HC-77B 3K RAM Expansion
Software NIM game cassette
Media Cassette image for NIM

Product Position

The 3K RAM Expansion extends the HC-77B from its 1 KB launch configuration to the planned 4 KB working system.

Bundling NIM with the RAM expansion gives users an immediate reason to fit the board: a small playable cassette game that demonstrates the machine moving beyond pure front-panel experimentation into practical loaded software.

Released Hardware

HC-77B 3K RAM Expansion

The 3K RAM Expansion completes the HC-77B's initial official RAM expansion path.

Item Detail
Product HC-77B 3K RAM Expansion
Adds 3 KB RAM
Resulting total RAM 4 KB
Address range $0400-$0FFF

For the wider HC-77B memory map, see HC-77B Technical Overview.

Released Software

NIM Cassette

The NIM cassette is bundled free with the 3K RAM Expansion.

It is the first public HomeComp cassette software release for the HC-77B.

Item Detail
Product NIM cassette
Type Game
Media Cassette
Bundle Free with HC-77B 3K RAM Expansion
Release period Late November / early December 1977

Release Role

This release marks the first expansion of the HC-77B ecosystem after the September 1977 launch.

It adds:

  • the first official RAM expansion
  • the first official cassette software
  • the first bundled hardware/software product
  • a practical demonstration of cassette-loaded HC-77B software

Next Release Focus

The next planned public release phase is March/April 1978.

That release will focus on:

  • Advanced Monitor Tools Cassette
  • HC Cassette BASIC Cassette

Clone this wiki locally