Project Expansions' Sound Expansion Cartridge

What It Does

The PROJECT EXPANSIONS SOUND EXPANSION CARTRIDGE is a 9cm x 11cm x 1.5cm black interface, cased by Care Electronics and bearing a white sticker. It has a speaker mounted on its back and connects to the ROM cartridge sockets of an ACORN PLUS 1/AP1 or ROMBOX+ extension. A female plug on its top connects to headphones, a female plug on its left to speakers. It also sports a 8K Sideways RAM socket into which a ROM image may be loaded.

The SOUND EXPANSION is enabled with a star command from the on screen cursor. Once operational, all sound is emitted not from the internal keyboard speaker but instead through its speaker. The protruding white knob on some, but not all, models can be turned to increase the volume as appropriate. On other models, turning a screw with a normal screwdriver has the same effect.

The SOUND EXPANSION will play sound on all four channels, allowing all the impressive music demos written for the BBC Micro to play on an ACORN ELECTRON fitted with it. It also works, although less impressively, with the Superior utility SPEECH!.

The SOUND EXPANSION came supplied with a User Guide, and a disc containing four demonstration programs and an adapted version of Superior's SPEECH! program.

The SOUND EXPANSION was originally available by mail order from Project Expansions for £89.99. A second hand SOUND EXPANSION will usually sell on eBay for £50-£70.

Artwork And Images

The outer box and pictures of the interface itself are shown below. There is currently no emulated version of this interface available.

Project Expansions' Sound Expansion Cartridge   Project Expansions' Sound Expansion Cartridge
Front View [Connects to Acorn Plus 1] Rear View

A Word Of Caution

To complicate matters somewhat, the two models of this interface use slightly different commands, necessitating a different disc and a different user guide. You can discover which version you have by typing the command *HELP SD at the prompt. You require the correct disc and user guide for your version.

Downloadable Companions

If you are missing any of the components originally bundled with the interface then you can download them by clicking on the links below:

Disc Type: Utility Disc; Featuring 4 Tunes & SPEECH! Utility
Supplier: Project Expansions
Release Info: 1986: SOUND EXPANSION DEMO DISC V1.00, Project Expansions
Compatibility: Electron, Plus 1 & Sound Expansion Cartridge

Author: Project Expansions
Release Information: 1990: SOUND EXPANSION CARTRIDGE, Project Expansions
ISBN (If Available): N/A
No. Of Pages: 7
Date Uploaded: 19.06.2004
File Type: Microsoft Word Document (Complete)
Suitable For: Electron Fitted With ROM Expansion Device & Sound Expansion Cartridge
Further Information: Includes Instructions for SPEECH!



One of the projects for the BBC which we, at Acorn Electron World, have made significant progress on, is our library of BBC MUSIC DISCS which are available in the BBC PD catalogue. Early in 2007, under the banner of the Organ Grinder's Monkey, we converted a not insignificant number of these to work on an Acorn Electron with a SLOGGER MASTER RAM BOARD and the PROJECT EXPANSIONS SOUND EXPANSION CARTRIDGE. The resultant disc(s) should be considered essential downloads for anyone who has these peripherals, and can be downloaded here.