Specifications

Preface
The OpenVMS VAX Device Support Reference Manual provides the reference
material for the OpenVMS VAX Device Support Manual, which describes how to
write a driver for a device connected to a VAX processor. This manual describes
the data structures, macros, and routines used in driver programming.
This manual provides information you need to write a device driver that runs
under OpenVMS VAX Version 6.1 and to load the driver into the operating
system. Digital does not guarantee that drivers written for earlier versions of
the operating system will execute without modification on this version of the
operating system. Although the intent is to maintain the existing interface, some
unavoidable changes might occur as new features are added.
The use of internal executive interfaces other than those described in this manual
are discouraged.
Intended Audience
This manual is intended for system programmers who are already familiar with
VAX processors and the OpenVMS VAX operating system.
Document Structure
This manual contains the following four chapters:
Chapter 1 contains a set of figures and tables that describe the contents of each
data structure in the I/O database.
Chapter 2 lists the system macros most frequently called by device drivers.
Chapter 3 describes the context, synchronization, and I/O requirements of the
operating system routines used by drivers or called as the result of a driver macro
invocation.
Chapter 4 supplies a condensed description of the function and environment of
each device driver entry point routine.
Associated Documents
Before reading the OpenVMS VAX Device Support Reference Manual, you should
have an understanding of the material discussed in the following documents:
• The OpenVMS VAX Device Support Manual is the driver programming
companion document
• VAX Hardware Handbook
• I/O-related portions of the OpenVMS System Services Reference Manual
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