An abbreviation for Audio Stream Input/Output architecture. Developed at Steinberg, it is the software engine that is the fundamental access method to the audio hardware for Cubase VST and is being employed in a growing number of hardware and software systems for doing audio on computers.
The computer manufacturers and operating system vendors target the “Multimedia” market and have implemented audio playback and recording capabilities specifically for it. This market however is based on stereo playback and recording, it did not require synchronization between other Media in the beginning, and multi channel operation wasn’t necessary. So far the only professional solutions have been proprietary expensive hardware based systems.
ASIO addresses all areas for pro-audio recording including flexibility with sample rates and bit depths as well as synchronization between different media like audio, MIDI and video. As a result the user gets a low latency, high performance, easy to set-up and control recording solution. The audio hardware can be either one or more sound cards with multiple audio input and output ports that conform to the ASIO specifications. ASIO exists for PC (Windows) and Macintosh systems currently.