For the purpose of input/output , certain conventions are proposed which take the form of that these procedures will be implemented in code. Input/output is intimately connected with hardware and different channels on one machine and different implementations. This document leaves undefined these areas and concentrates on specifying a basic input/output facility that can be expanded firstly, by the individual implementer who will define actions undefined in this document and secondly, by the individual user who will build up a set of more complex procedures to satisfy his normal needs.
The term channel is used in this document to describe the destination of source of data occurring in an Algol program.