The Sound Chip of the Oric is the AY-3-8912 Programmable Sound Generator (More commonly known as the PSG). It was used on a variety of machines in the 1980's. Most notably the Spectrum 128K, Amstrad CPC and the ATARI ST (Although being slightly different in that it had an extra I/O port).
The PSG is a 3 channel Device. Each channel can generate Square waves over a range of 10 octaves (14 Bit resolution). Although the wave form cannot be altered, a further Noise generator can be mixed with any of the 3 Base channels.
Each channel can also be adjusted for volume (4 Bit) or control of volume can be handled by a single Envelope generator. This can generate 8 unique wave patterns.
For further information about sending Data to the sound Chip (Predominantly Sample Data), refer to thisDocument.