Philips SAA1099

this was used by the Game Blaster and SAM Coupé. it's pretty similar to the AY-3-8910, but has stereo sound, twice the channels and two envelopes, both of which are highly flexible. the envelopes work like this:

• an instrument with envelope settings is placed on channel 2 or channel 5
• an instrument that is used as an "envelope output" is placed on channel 3 or channel 6 (you may want to disable wave output on the output channel)

effects

• 10xy: set channel mode.
• x toggles noise.
• y toggles square.
• this effect affects either the first 3 or last 3 channels, depending on where it is placed.
• 11xx: set noise frequency.
• this effect affects either the first 3 or last 3 channels, depending on where it is placed.
• 12xx: setup envelope. this is a bitmask.
• bit 7 toggles the envelope.
• bit 5 toggles whether to use a fixed frequency or lock to the frequency of channel 2 or 5.
• bit 4 sets the envelope resolution.
• bits 1 to 3 set the envelope shape:
  • 000: always off
  • 001: always on
  • 010: down
  • 011: down loop (saw)
  • 100: up down
  • 101: up down loop (triangle)
  • 110: up then off
  • 111: up loop (reverse saw)
• bit 0 sets whether the right output will mirror the left one.
• this effect affects either the first 3 or last 3 channels, depending on where it is placed.

info

this chip uses the SAA1099 instrument editor.