# 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](../4-instrument/saa.md) instrument editor. ## chip config the following options are available in the Chip Manager window: - sets the rate at which the chip will run.