furnace/doc/7-systems/multipcm.md
Electric Keet d4364a1b74 Many doc updates.
Settings changes, interface niceties, and a ton of info about sample limits.
2025-09-30 04:50:22 -05:00

1.2 KiB

Yamaha YMW258-F (MultiPCM)

a sound chip introduced in 1991 by Yamaha for their first General MIDI-compliant synthesizer, the Yamaha TG100. It also appeared on a number of higher-end consumer keyboards and specialized professional devices. The YMW258-F implements the GEW8 sound synthesis technology, which is PCM sample-based synthesis under Yamaha's "Advanced Wave Modulation" (AWM) umbrella.

Sega used the chip in several arcade games on the Sega System Multi 32, Sega Model 1, and Sega Model 2 arcade boards. The chip as found on these boards is called MultiPCM, and has the Sega internal part number 315-5560. Contrary to popular belief, it is not a custom Sega part and is not based on the earlier SegaPCM chip, but it was named the MultiPCM as a successor to that chip.

it has a whopping 28 channels of stereo 16-bit PCM and:

  • hardware LFO
  • 8bit and 12bit wave format support
  • up to 4MB of wave memory
  • full blown ADSR envelopes

effects

  • 20xx: set PCM LFO rate.
  • 21xx: set PCM LFO PM depth..
  • 22xx: set PCM LFO AM depth.

info

this chip uses the MultiPCM instrument editor.

maximum sample length is 65535 samples.