Sound
Amiga UNIX plays sound through the Amiga's own sound chip, Paula, in two ways.
/dev/audio: a sample stream
The Amiga UNIX audio device: a program writes samples and the system plays them. One program at a time; a second one is refused while the first has it open.
In an emulator, switch the emulator's sound output on (in Amiberry, sound_output=interrupts or
better). With sound off, opening /dev/audio fails instead of playing.
/dev/paula: Paula's four channels
The Paula driver gives one program direct use of Paula's four channels, the way a tracker plays music on AmigaOS: the samples play from chip memory without the CPU mixing them, so music costs little CPU time.
As root, on a 68040 or 68060:
apkg install paula-k46
and on a 68030, paula-k30. It is a driver, so apkg makes a new boot generation: switch off and
on to boot it (boot recovery). It needs the 1.1 kernel; apkg refuses it on an
older one.
- It brings
/dev/paula, open to every user, and the programming interface/usr/include/paula.h. - The driver loads by itself when a program first opens
/dev/paula; it is not loaded in safe mode. - While a program has
/dev/paulaopen,/dev/audiois refused, and the other way round. - The tempo follows the machine's PAL or NTSC timing; the pitch follows what the program sets (tracker period tables assume PAL).
No program in 1.1 uses /dev/paula yet: it is there for programs written or ported to it. The
whole interface is in /usr/include/paula.h.
Supported · emulation Tested in emulation on both lines; not yet on real hardware.