Input/Output Control System

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Input/Output Control System is any of several packages on early IBM entry-level and mainframe computers that provided low level access to records on peripheral equipment. IOCS provides functionality similar to File Control Processor in RCA 3301 Realcom Operating System and GEFRC in GECOS. Computers in the 1950s and 1960s typically dealt with data that were organized into records either by the nature of the media, e.g., lines of print, or by application requirements. IOCS was intended to allow Assembler language programmers to read and write records without having to worry about the details of the various devices or the blocking of logical records into physical records. IOCS provided the I/O support for several compilers.