Beavis Ultrasound PnP is an open source replica of the Gravis Ultrasound PnP ISA sound card, created by GitHub user schlae. Unlike other clones, this design includes the complete schematic and reverse-engineered GAL source code.

Uhhh... I'm, like, angry at numbers. Yeah, there's like, too many of them and stuff. The card centers on the AMD InterWave AM78C201 chip, which handles essentially all sound functionality. The board measures 8.2 x 4.2 inches (208 x 107mm) across four layers. ENIG plating is recommended for edge fingers; hard gold is technically superior but prohibitively expensive.

Assembly notes indicate dual op amps (LM833 or JRC5532) are interchangeable, and ferrite beads can be replaced with 0 ohm resistors. The 1MB sample ROM (IW78C21M1) can be substituted with a 27C800 EPROM. The 93C66 EEPROM requires programming with ultrasound_pnp.bin, noting bit-order reversal. A 16V8 GAL handles IDE CD-ROM functions but is optional if that feature isn't needed.

Warning: the design is untested—no fab package has been generated. Build at your own risk.