In the early '80s, sound on desktop computers was a luxury item. Most users could only access the classic speaker, and the only alternatives (besides being expensive) forced us into the IBM or Tandy arena.
In 1987, the AdLib card turned the market upside down, but the Covox Speech Thing also appeared, a DAC connected to the parallel port. The Covox Speech Thing wasn't cheap in its official version; however, its resistor-ladder design allowed quick DIY reproduction at a fraction of the original cost.
If you buy a modern motherboard, its integrated sound solution is good enough to connect a pair of speakers or headphones and forget about it.
Of course, there will always be more demanding environments and dedicated cards, but if we go back a few decades, sound on a PC-compatible computer was a true privilege.
The AdLib board was one of the pioneers in the PC audio revolution, and it could be yours for $195 in 1988 ($420 when adjusted for inflation).
Covox Speech Thing: The Sound Before the Sound Blaster
If that number was out of your budget, you only had one option: the Covox Speech Thing. From a technical standpoint, Covox was an 8-bit DAC that connected to the computer's parallel port.
Some of its variants offered passthrough support, meaning the Covox could sit as a "man in the middle" between the printer and the computer without affecting its operation.
A DIY Project at a Fraction of the Cost
The official price of the Covox Speech Thing at launch was around 70-80 dollars; however, some electronics enthusiasts soon discovered it could be built at home with great ease.
Why? Because the Covox is nothing more than a series of connected resistors. Its most basic design needs only 20 resistors, a parallel port connector, and a mono 3.5mm output.
The sound quality difference compared to the PC speaker was abysmal, courtesy of seven additional bits. Several MS-DOS programs dedicated to playing MOD files soon added Covox support, but everything went through games at the end of the '80s, and that's where this curious DAC bit the dust.
It wasn't easy for developers to make their titles compatible with the Covox. In fact, only 56 games are known to support it in one way or another. 688 Attack Sub, Chuck Yeager's Air Combat, Pinball Fantasies, Pinball Illusions, Rex Nebular and the Cosmic Gender Bender, and Star Control II are the most relevant.
The Covox Legacy
Time passed, and Creative conquered the PC audio universe with its Sound Blaster series, but the Covox Speech Thing still catches our attention even today.
Besides being an excellent DIY project for those who enjoy electronics, the Covox retains some popularity in the demoscene movement, and now we have the possibility of using a "Tandy emulator" with a modern clone of the Covox, called CVX4.
If you want one "ready to use" instead of building it, its current price is 20 euros.
