PC:Covox DAC Clone
The Covox Speech Thing is an external 8-bit digital-to-analogue converter (DAC) that can be used as a sound device for PC-compatibles by taking advantage of the parallel/LPT port. The device is compatible with a variety of games and is a perfect solution for laptops that don't have a dedicated sound card or later desktop computers that do not have ISA slots to fit an AdLib or Sound Blaster.
Over the years, the hardware has been well documented. People have started to create their own DIY variants since the way the parallel port communicates with the DAC is very simple and only requires soldering a few cheap components.
Since sound cards were very expensive to buy in the 1990s, the Covox was a popular device amongst demoscene groups for creating music and demos that utilised it.
Clones
Silly Sound Bastard by Necroware
Simple LPTsndby Retrokits.de/matze79
Covox Blaster by dion-b
CVX4 by Serdaco