Rescuing Colour Genie programs from audio tape
The second, very yellow colour genie I picked up the other day came with about 18 programs on tape.
Normally I wouldn't worry about preserving software from most of the computers in my collection as it's relatively easy to get hold of it off the Internet. This is not the case for the colour genie though. Software is rare and the stuff on the Net, limited. If you have got real copies, it pays to make sure they are always going to be there!
Cassettes deteriorate and these cassettes appeared to be well down that track already. That being the case I decided to copy all the programs to my hard drive hence preserve them from chemical degradation.
The program I used for this was the freeware audio editor Audacity. It's a highly useful piece of software. Check it out if you haven't already.
Audacity is easy to use but I still spent a whole evening simply getting the audio levels right. I did this by loading a BASIC program into the computer via cassette, then saving it into Audacity through the soundcard. I tried a range of recording levels until a strong wave image was generated, at about 50-60% amplitude. This seemed to be the most reliable, when tested by reading the program back into the computer.
The colour genie has a level meter for loading, and I found keeping this between 1-3 on the meter worked ok. Some programs seemed more sensitive that others to gain levels though. Too much or too little and the dreaded "C" for checksum appeared.
Anyway, at the end of the process (two evenings) I'd managed to save 11 programs to the hard drive in WAV format. Each was tested to check that they indeed worked when loaded back into the colour genie. These lucky few should now be safe from the ravages of time, and they have been added to my small collection of other Colour Genie programs culled from emulator collections on the Internet.
Saug, now sourced from my PC hard disk
It wasn't all good news though. Seven programs seemed to be damaged beyond repair. I couldn't get a successful load from the tapes no matter what levels I used. It could be that the media has just deteriorated too much. Certainly some of the tapes were "sticky" and I had to clean the cassette player heads quite often.
Never give up though. I'll have a crack at them again at some other time.
29th August, 2008