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 instrument editor.

when two channels are joined for filtered output, the channel bar will show filter on a bracket tying them together.

when two channels are joined for wide period range, the channel bar will show 16-bit on a bracket tying them together.

ROM export

a song can be exported as SAP-R, a compressed register dump. more details on the format are available (in Polish) at its page on the Atariki wiki.

chip config

the following options are available in the Chip Manager window:

• PAL: run the chip at PAL clock (1.77MHz) instead of NTSC (1.79MHz).