Beavis Ultrasound PnP ISA Sound Card Replica
An open-source replica of the Gravis Ultrasound PnP
1Beavis Ultrasound PnP ISA Sound Card Replica
The Beavis Ultrasound PnP ISA Sound Card Replica is an open-source copy of the Gravis Ultrasound PnP. This design includes the reverse-engineered source code of the GAL and the complete schematic. Developed using the AMD InterWave chip, the card integrates all sound card functions into a single chip.
2Design and Production
The card's design is quite simple as all sound card functions are provided by the AMD InterWave chip. The card measures 8.2 x 4.2 inches (208 x 107mm) and is 4 layers thick. ENIG plating can be used in the production process, although hard gold, technically superior, is prohibitively expensive.
3Assembly Notes
Dual op amps can be substituted. While the BOM specifies LM833, JRC5532 can also be used. Essentially, any ~10MHz low-noise op amp that can handle a +/-8V input power supply will suffice. If ferrite beads are missing, they can be replaced with a 0 ohm resistor or a piece of wire.
4Programmable Devices
U8, the IW78C21M1, is the 1MB sample ROM. If this chip is unavailable, the sample ROM can be downloaded from the internet and burned onto a 27C800. U6/U60, the 93C66 EEPROM, contains the plug-and-play configuration data and should be programmed with the contents of ultrasound_pnp.bin.
5GAL Usage
U14, the GAL, is used for various purposes such as buffering IOCS16 from the IDE port to the ISA bus, buffering the bus reset signal to the IDE port, and decoding some address lines. If the CDROM IDE function is not needed, the GAL is unnecessary.
6Conclusion and Importance
The Beavis Ultrasound PnP ISA Sound Card Replica is a significant project for reviving old technology and providing an open-source design. This card is a valuable resource for those interested in understanding the evolution of sound card technology and reproducing old hardware.
Original article: Hacker News: Front Page — Beavis Ultrasound PnP ISA Ses Kartı Replikası