dingusppc/zdocs/awacs.md

AWACS is an audio controller present on several Old World Macs and can usually be located at IOBase (ex.: 0xF3000000 for Power Mac G3 Beige) + 0x14000.

Register Maps

NuBus Macs

Register	Offset	Length
Codec Control	0x0	3
Codec Status	0x4	3
Buffer Size	0x8	2
Phaser	0xA	4
Sound Control	0xE	2
DMA In	0x12	1
DMA Out	0x16	1

PCI Macs

All registers are 32-bit here.

Register	Offset
Sound Control	0x0
Codec Control	0x10
Codec Status	0x20
Clipping Count	0x30
Byte Swapping	0x40

Separate volume controls exist for the CD drive and the microphone.

The DMA buffer size is set to be 0x40000 bytes, while the DMA hardware buffer size is set to be 0x2000 bytes.