OpenVMS IO User's Reference Manual

This document, the "OpenVMS I/O User's Reference Manual" (April 2001), is intended for system programmers who need to directly interface with I/O device drivers within the Compaq OpenVMS operating system (specifically Alpha and VAX versions 7.2/7.3).

The manual provides detailed information on the Queue I/O (QIO) interface for file system ancillary control processes (ACPs) and various device drivers, including disk, magnetic tape, mailbox, terminal, pseudoterminal, shadow-set virtual unit, generic SCSI, and Local Area Network (LAN) devices. It includes programming examples and covers optional features for improving I/O performance like Fast I/O and Fast Path (for Alpha systems).

Notably, the document focuses on direct I/O operations and does not contain information on I/O operations using the OpenVMS Record Management Services.