FM synthesis is the sound of the 1980s, it’s the sound of shopping malls and Macintosh Plus. It’s the sound of the Motorola DynaTAC, busts of Helios, and the sound of ｖａｐｏｒｗａｖｅ サ閲ユ. The chips most responsible for this sound is the OPL2 and OPL3, tiny little FM synthesizers on a chip, produced by Yamaha, and the core of the AdLib and Sound Blaster sound cards. It’s the chip behind the music in all those great DOS games.
Unfortunately, computers don’t have ISA slots anymore, and cards don’t work in 486 and Pentium-based laptops, the latest hotness for retrocomputing enthusiasts. For his Hackaday Prize entry, [serdef] is bringing the sound of the 80s to the parallel port with the OPL2LPT. It’s a sound card for the parallel port that isn’t just a resistor DAC like the Covox Speech Thing.
The design of the OPL2LPT is pretty much what you would expect; it’s an OPL2 chip, opamp, a 1/8″ jack, and a few passive components. The real trick here is in the driver; by default, every DOS game around expects an Adlib card on port 338h, whereas the parallel post is at 378h. A driver takes care of this in software, but it is possible to patch a game to change every write to an Adlib card to a write to a parallel port.
Already, [serdef]’s parallel port graphics card is a real, working product and has caught the attention of Lazy Game Reviews and the 8-Bit-Guy, you can check out those video reviews below.
Continue reading “Vaporwave For The Parallel Port”
Before the AdLib sound card, sound on PCs was in a terrible shape. Since the dawn of IBM, all PCs included a speaker, but this PC speaker was only capable of sounding one note at a time. Chords on the PC speaker produced a weird ‘bubbling’ effect. Just a few years later, 8-bit sound could be created with the Covox Speech Thing, effectively a resistor ladder, with the parallel port on one side, and an 1/8″ plug on the other. These solutions for PC sound sucked.
It wasn’t until the first AdLib cards that superior sound showed up on the PC. Recently, [eric] had been fixing up an old IBM XT and quickly realized the original AdLib sound cards were collector’s items and far too expensive for what they were. He decided to build a reproduction Ad Lib. completely compatible and nearly identical to the original 1990 version of the best sound card on the market.
The first Ad Lib sound card is a relatively simple circuit based on the Yamaha YM3012 (OPL2) and YM3014B chips. These chips are frequently available on eBay, and [Sergey] already has a complete circuit for turning these chips into an ISA sound card. While this modern card is compatible with the AdLib Music Synthesizer Card, it doesn’t look like one. [eric] wanted a card that looked like the real thing, and sounded like one, too.
PCB design has come a long way in a generation, and where the AdLib card was once a wonder of modern technology, anyone with enough patience can now design an identical board, send the file off to China, and receive a reproduction of the first successful sound card. All the files are up on Github should you want to build your own. Now all we need is someone making modern 486 motherboards.
Before the days when computers could play and record audio that far surpassed the quality of CDs, sound cards were very, very cool. Most audio chips from the 80s, from the Commodore SID is pretty much a synth on a chip, but you can also find similar setups in ancient ISA sound cards. [Emilio] pulled one of these cards with an ADLIB OPL2 chip on it, and used a PIC micro to create his very own FM synthesis synth (IT, translatatron, although Google is screwing up the formatting).
The Yamaha YM3812 chip, otherwise known as the OPL2, was a fairly complete synthesizer in a very tiny package using FM synthesis for some very unique sounds. Once [Emilio] had the PIC sending commands to the sound chip, he added MIDI support, allowing him to play this vintage ‘synth on a chip’ with a keyboard instead of a tracker.
Judging from the video below, it sounds great, and that’s with [Emilio] mashing the keys for a simple demo.
Continue reading “MIDI And Vintage FM Synthesis”