dingusppc/zdocs/awacs.md

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2020-03-06 04:38:14 +00:00
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.
2020-03-01 17:58:09 +00:00
# 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.
2020-03-01 17:58:09 +00:00
The DMA buffer size is set to be 0x40000 bytes, while the DMA hardware buffer size is set to be 0x2000 bytes.