You don’t requirement elegant ICs as well as DACs to develop a noise card for a PC. As [serdef]’s develop over on hackaday.io shows, all you truly requirement is a lot of resistors. [serdef] developed a clone of a noise card released for PC in the 80s, however with a few improvements. This mess of resistors features the very best 8-bit noise you can get with a low-pass filter, volume divider, as well as a useful DB-25 connector.

The style of this LPT0 noise card is quite much the exact same as when it was introduced to the world as the Covox Speech Thing. This ‘sound card’ was developed to clip onto the parallel port of a computer as well as send the 8-bit I/O of this port with a resistor ladder. plug a pair of speakers into this thing, as well as you have a noise card that is totally constructed out of resistors. It was cheap, as well as in the demoscene it was popular.

There are a great deal of fantastic demos available utilizing this resistor DAC thing, as well as [serdef] has videos of his job playing a great deal of them. You can inspect that out below.