furnace/doc/7-systems/es5506.md

Ensoniq ES5506 (OTTO)

sample-based synthesis chip used in a bunch of Taito arcade machines and PC sound cards like Soundscape Elite. a variant of it was the heart of the well-known Gravis Ultrasound.

it supports a whopping 32 channels of 16-bit PCM and:

• real time digital filters
• frequency interpolation
• loop start and stop positions for each voice (bidirectional and reverse looping)
• internal volume multiplication and stereo panning
• hardware support for envelopes

effects

• 10xx: set waveform.
• 11xx: set filter mode. values are 0 through 3.
• 120x: set pause (bit 0). pauses the sample until the bit is unset; it will then resume where it left off.
• 14xx: set filter coefficient K1 low byte.
• 15xx: set filter coefficient K1 high byte.
• 16xx: set filter coefficient K2 low byte.
• 17xx: set filter coefficient K2 high byte.
• 18xx: set filter coefficient K1 slide up.
• 19xx: set filter coefficient K1 slide down.
• 1Axx: set filter coefficient K2 slide up.
• 1Bxx: set filter coefficient K2 slide down.
• 20xx: set envelope count.
• 22xx: set envelope left volume ramp.
• 23xx: set envelope right volume ramp.
• 24xx: set envelope filter coefficient K1 ramp.
• 25xx: set envelope filter coefficient K1 ramp (slower).
• 26xx: set envelope filter coefficient K2 ramp.
• 27xx: set envelope filter coefficient K2 ramp (slower).
• 3xxx: set coarse filter coefficient K1.
• 4xxx: set coarse filter coefficient K2.
• 81xx: set panning (left channel).
• 82xx: set panning (right channel).
• 88xx: set panning (rear channels).
• 89xx: set panning (rear left channel).
• 8Axx: set panning (rear right channel).
• 9xxx: set sample offset. resets sample position to xxx * 0x100.
• DFxx: set sample playback direction.