42 lines
1.5 KiB
Markdown
42 lines
1.5 KiB
Markdown
# POKEY
|
|
|
|
a sound and input chip developed by Atari for their 8-bit computers (Atari 400, 800, XL/XE and so on). 4 channels of signature Atari sounds.
|
|
|
|
# effects
|
|
|
|
- `10xx`: **set waveform.**
|
|
- 0: harsh noise (poly5+17)
|
|
- 1: square buzz (poly5)
|
|
- 2: weird noise (poly4+5)
|
|
- 3: square buzz (poly5)
|
|
- 4: soft noise (poly17)
|
|
- 5: square
|
|
- 6: bass (poly4)
|
|
- 7: buzz (poly4)
|
|
- `11xx`: **set AUDCTL.** `xx` is a bitmask.
|
|
- bit 7: 9-bit poly mode. shortens noise.
|
|
- bit 6: high channel 1 clock (~1.79MHz on NTSC).
|
|
- overrides 15KHz mode.
|
|
- bit 5: high channel 3 clock (~1.79MHz on NTSC).
|
|
- overrides 15KHz mode.
|
|
- bit 4: join channels 1 and 2 for a wide period range.
|
|
- use with conjunction with bit 6.
|
|
- channel 2 becomes inaccessible when this is on.
|
|
- bit 3: join channels 3 and 4 for a wide period range.
|
|
- use with conjunction with bit 5.
|
|
- channel 4 becomes inaccessible when this is on.
|
|
- bit 2: high-pass filter (channels 1 and 3).
|
|
- filtered output on channel 1 (I suggest you to set channel 3 volume to 0).
|
|
- use for PWM effects (not automatic!).
|
|
- bit 1: high-pass filter (channels 2 and 4).
|
|
- filtered output on channel 2 (I suggest you to set channel 4 volume to 0).
|
|
- use for PWM effects (not automatic!).
|
|
- bit 0: 15KHz mode.
|
|
- `12xx`: **toggle two-tone mode.**
|
|
- when enabled, channel 2 modulates channel 1. I don't know how, but it does.
|
|
- only on ASAP core.
|
|
|
|
# info
|
|
|
|
this chip uses the [POKEY](../4-instrument/pokey.md) instrument editor.
|