Complex Software Systems/Project Expansions Sound Expansion for the Acorn Electron

Back in 1989 when I saw the advert for the Project Expansions Sound Expansion for the Electron I thought I'd quite like to buy one but once again at 39.95 it was too expensive so I had to let it pass me by.

This expansion brought the BBC Micro sound capabilities to the Electron. Instead of me decribing the cartridge please read the article below from the May issue of Electron User.

Keeping up with new developments on Stardot for the Electron I read about this cartridge being reconstructed so I contacted the developer (jms2) and bought one of the prototype boards.

After a few teething troubles the cartridge was working quite nicely. Here's a video showing of the difference the cartridge makes. Firstly with the cartridge enabled and at 1 minute 38 seconds the default Electron sound.

Envelope Definer

When reading through the May 1990 Electron User I noticed an article on an envelope definer written by the designer of the sound cartridge. The listing was too long for me to type in so I looked on to see if I could find the magazine cover tape and luckily for me it was there (what surprised me was I donated the UEF files to many years ago!) so I went about extracting the listings form the tape image. To do this I used BeebEm, loaded the tape image and entered CH."" to load the tape menu.

Finding two programs I then catalogued the tape (*.) to list the file names, DEF1 & DEF4. I then loaded each one and saved them to a disc image.

Running DEF1 on the Electron gave me a colour opening screen and DEF4 a Black & White screen:

As can be seen it recognised the sound cartrdge ok and enabled the additional envelope parameters.

Interestingly I found a bug in DEF1, on line 1090 the GOTO term was written in lower case causing the program to crash when using the left cursor key, also, running the program in turbo mode the cursor moves too fast to select a parameter, switching to standard mode slows it down.

Download the Envelope Definer disc.