AMD seeks audio foothold with lower cost InterWave IC

Electronic News, June 10, 1996 by Andrew MacLellan

Austin, Texas--As evidence that the audio processor community is intent on matching the strides made by its counterparts in the graphics arena, Advanced Micro Devices (AMD) has developed a lower cost version of its InterWave audio processor in a bid to gain a foothold in the add-in card and motherboard PC audio market.

The new Am78C200 InterWave LC (low cost) processor pits AMD's wavetable technology against FM synthesis, an inexpensive, mainstream technique which approximates targeted instrumental sounds but is claimed by AMD to deliver lower quality audio with a limited dynamic range.

"The old FM audio solution dramatically compromises the incredible sound of today's sophisticated game and music MIDI files," said Bob Krueger, VP of AMD's I/O and network products division. "Our goal in adding the LC product to the InterWave processor line is to deliver wavetable sound at a price that makes it the equipment choice for end-user PCs."

The new processor, available now in a 106-pin PQFP package and priced at $19.50 in 10,000-unit quantities, is software- and pin-compatible with AMD's existing Am78C201 InterWave processor, according to the company.

The chip, like its higher-end predecessor, features full-duplex voice for real-time interactive Internet applications, a 16-bit, 32-voice stereo wavetable synthesizer, 16-bit recording and playback, MPC Level 3 standard-compatible audio mixer, joystick port, serial DSP port and Musical Instrument Digital Interface (MIDI) port.

AMD said it is able to compete in the volume market with its new chip by adding mono microphone and record features and eliminating the special effects processor, doing away with the need for on-chip DRAM interface and external DRAM.

The Am78C200 stores 128 General MIDI instruments in an external 1-megabyte ROM, supporting FM synthesis through software emulation for backward compatibility with FM-based applications, according to AMD. The chip is fully plug-and-play compliant and is said by its maker to offer an engine for Internet applications or running the Windows 95 game software developers kit (SDK) audio feature set.