31 lines
1.4 KiB
Markdown
31 lines
1.4 KiB
Markdown
# 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.
|