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Subject: OpenVMS Frequently Asked Questions (FAQ), Part 2/9
Summary: This posting contains answers to frequently asked questions about
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which it runs.
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General Information

standards such as POSIX, which provides many features
of UNIX systems.

For those versions with POSIX, an OpenVMS license
allows you to install and run POSIX for OpenVMS at
no additional charge; all you need is the media and
documentation which can be found on the Consolidated
Distribution and On-Line Documentation CD-ROMs. Support
for the POSIX package on more recent OpenVMS releases
is not available, various parts of POSIX such as calls
from the API are being integrated more directly into
OpenVMS. For more information on POSIX for VMS see
question SOFT2

What became confusing is that the OpenVMS name was
introduced first for OpenVMS AXP V1.0 causing the
widespread misimpression that OpenVMS was for Alpha
AXP only, while "regular VMS" was for VAX. In fact,
the official name of the VAX operating system was
changed as of V5.5, though the name did not start to be
actually used in the product until V6.0.

The proper names for OpenVMS on the two platforms
are now "OpenVMS VAX" and "OpenVMS Alpha", the latter
having superseded "OpenVMS AXP".

_____________________________
2.2.1 How do I port from VMS to OpenVMS?

You already did. Wasn't that easy? Please see
Section 2.2 for details.

__________________________________________________________
2.3 Which is better, OpenVMS or UNIX?

This question comes up periodically, usually asked by
new subscribers amd new posters who are long-time UNIX
or Linux users. Sometimes, the question is ignored
totally; other times, it leads to a long series of
repetitive messages that convince no one and usually
carry little if any new information. Please do everyone
a favor and avoid re-starting this perpetual, fruitless
debate.

2-3

General Information

That said, OpenVMS and the better implementations of
UNIX are all fine operating systems, each with its
strengths and weaknesses. If you're in a position where
you need to choose, select the one that best fits your
own requirements, considering, for example, whether or
not the layered products or specific OS features you
want are available.

__________________________________________________________
2.4 Is HP continuing funding and support for OpenVMS?

Yes.

Active development of new OpenVMS releases is underway,
as well as the continuation of support.

Please see the following URLs for details, roadmaps,
and related information:

o http://www.openvms.compaq.com/

o http://www.openvms.compaq.com/OPENVMS/strategy.html

o http://www.openvms.compaq.com/openvms/roadmap/openvms_
roadmaps.htm

o http://www.openvms.compaq.com/openvmstimes/

o http://www.compaq.com/inform/

__________________________________________________________
2.5 What OpenVMS CD-ROM distribution kits are available?

Various distributions are available.

For information on the available part numbers
and current products (OpenVMS distribution kits,
media, documentation, etc) and associated licensing
information, please see the OpenVMS Software Product
Description (SPD), available at:

o http://www.compaq.com/info/spd/
OpenVMS typically uses SPD 25.01.xx and/or SPD
41.87.xx.

2-4

General Information

The CD-ROMs listed in Table 2-1 contain just the
OpenVMS Alpha operating system. These are bootable,
and can be used to run BACKUP from CD-ROM.

________________________________________________________________
Table 2-1 OpenVMS Media Kits

_______________________________________________________
Part______________Description__________________________

QA-MT1AP-H8 OpenVMS Alpha V6.1-1H2 hardware
release CD-ROM

QA-MT1AG-H8 OpenVMS Alpha V6.2-1H3 hardware
release CD-ROM

QA-MT1AD-H8 OpenVMS Alpha V7.1-1H1 hardware
release CD-ROM

QA-MT1AR-H8 OpenVMS Alpha V7.1-2 maintenance
release CD-ROM

QA-MT1AT-H8 OpenVMS Alpha V7.2-1 maintenance
release CD-ROM

QA-MT1AU-H8 OpenVMS Alpha V7.2-1H1 hardware
___________________________release_CD-ROM_______________________

The table Table 2-2 contains the consolidated ECO
distribution kit subscriptions, and these provide sites
with eight updates of the current ECO kits per year:

________________________________________________________________
Table 2-2 OpenVMS ECO Kits

_______________________________________________________
Part______________Description__________________________

QT-3CQAA-C8 OpenVMS Alpha

_________QT-3CRAA-C8_______OpenVMS_VAX__________________________

The OpenVMS VAX and OpenVMS Alpha source listings
CD-ROM sets listed in Table 2-3 include the source
listings of most of OpenVMS, and these CD-ROM sets
are invaluable for any folks working directly with
OpenVMS internals, as well as folks interested in
seeing examples of various programming interfaces.

2-5

General Information

________________________________________________________________
Table 2-3 OpenVMS Source Listings CD-ROM Kits

_______________________________________________________
Part______________Description__________________________

QB-MT1AB-E8 OpenVMS Alpha Source Listings CD-ROM

QT-MT1AB-Q8 OpenVMS Alpha Source Listings CD-ROM
Updates

QB-001AB-E8 OpenVMS VAX Source Listings CD-ROM

QT-001AB-Q8 OpenVMS VAX Source Listings CD-ROM
___________________________Updates______________________________

__________________________________________________________
2.6 In what language is OpenVMS written?

OpenVMS is written in a wide variety of languages.

In no particular order, OpenVMS components are
implemented using Bliss, Macro, Ada, PLI, VAX and DEC
C, Fortran, UIL, VAX and Alpha SDL, Pascal, MDL, DEC
C++, DCL, Message, and Document. And this is certainly
not a complete list. However, the rumor is NOT true
that an attempt was made to write pieces of OpenVMS in
every supported language so that the Run-Time Libraries
could not be unbundled. (APL, BASIC, COBOL and RPG are
just some of the languages NOT represented!)

There are a large variety of small and not-so-small
tools and DCL command procedures that are used as part
of the OpenVMS build, and a source code control system
capable of maintaining over a hundred thousand source
files across multiple parallel development projects,
and overlapping releases.

__________________________________________________________
2.7 Obtaining and Transfering OpenVMS licensees?

The following sections describe hobbyist and
educational license programs, as well as information on
commercial licenses and transfers.

For information on the available commercial OpenVMS
licenses and for information on license transfers,
please see Section 2.7.3. For information on the
licensing implementation, troubleshooting licensing

2-6

General Information

problems, on the License Unit Requirements Table
(LURT), and other related details, please see
Section 5.38.

_____________________________
2.7.1 Questions asked by Hobbyist OpenVMS licensees?

If you are a member of an HP-recognized user group
(eg: Encompass, Enterex, DECUS), and are considering
acquiring and using a VAX or Alpha system for
hobbyist (non-commercial) use, (free) license product
authorization keys (PAKs) for OpenVMS VAX, OpenVMS
Alpha, and layered products are available.

In addition to the license keys, OpenVMS VAX and
Alpha distribution CD-ROM distribution kits are
available with OpenVMS, DECwindows Motif, DECnet
and TCP/IP networking, compilers, and a variety
of layered products. (While the hobbyist CD-ROM
distributions are intended for and tailored for
OpenVMS Hobbyists, the contents and capabilities of
the Hobbyist installation kits included within the
OpenVMS Hobbyist distribution do not differ from the
standard distribution installation kits. The products
are chosen to reflect the most popular products and the
space available on the media.)

If you have questions on what else is authorized by the
license agreement and on what other distribution media
is available to you, well, please read the applicable
software license agreement(s).

For further information, please link to:

o http://www.openvmshobbyist.org/

On the OpenVMS Hobbyist license registration form
at the above website (as of January 2003), you are
offered the choice of the "OpenVMS VAX" license(s), the
"OpenVMS Alpha" license(s), and the "Layered Products"
licenses. You will want the operating system license
for your particular OpenVMS platform and you will
want the "Layered Products" licenses. You will want
to select and to acquire two sets of license PAKs.

2-7

General Information

For vendors wishing to license products specifically
for hobbyist use (and to not issue hobbyist PAKs),
the program provides hobbyists with the license PAK
OPENVMS-HOBBYIST.

_____________________________
2.7.2 OpenVMS Educational and CSLG licenses?

For information on OpenVMS licenses for educational
customers, please see the HP Campus Software
License Grant (CSLG) license program and the OpenVMS
Educational license program:

o http://www.openvmsedu.com/

_____________________________
2.7.3 How do I obtain or transfer an OpenVMS license?

To transfer a commercial OpenVMS license from one owner
to another, or to purchase a commercial license, you
can contact HP at 1-800-OK-COMPAQ (in North America),
or your local or regional sales office or reseller.

Commercial software developers can join the HP DSPP
program, and can (potentially) receive discounts
on various software product licenses and software
distributions, as well as on hardware purchases. Please
see Section 2.14 for details on DSPP.

The DSPP program is the descendent of the DIGITAL ASAP
program and the Compaq CSA program.

For information on the OpenbVMS Hobbyist and
OpenVMS Educational license programs, please see
Section 2.7.1.

__________________________________________________________
2.8 Does OpenVMS support the Euro currency symbol?

OpenVMS can generate the %xA4 character code used for
the Euro, and the DECwindows DECterm can display the
glyph. Please check with the vendor of your terminal or
terminal emulator for additional details.

2-8

General Information

For additional information on the support of the
European Monetary Union Euro currency glyph on OpenVMS,
please see:

o http://www.openvms.compaq.com/euro/

__________________________________________________________
2.9 Why hasn't OpenVMS been ported to Intel (IA-32) systems?

Why? Business reasons...

There is presently a belief that there would be
insufficient market to justify the cost involved
in porting OpenVMS to systems using the Intel IA-
32 architecture. In addition to the direct costs
involved in any port, each maintainer of a product
or a package for OpenVMS has to justify the port to
"OpenVMS Pentium" or to OpenVMS I64 (on Intel Itanium),
akin to the required justifications for a product port
from OpenVMS VAX to OpenVMS Alpha.

But yes, it would certainly be nice to have.

And yes, both OpenVMS Engineering and
OpenVMS management are well aware of the AMD
Opteron/Hammer/AMD64 platform, and have also heard
many of the various "Yamhill" rumors as well.

For an alternative approach (using a VAX emulator),
please see Section 13.13.

__________________________________________________________
2.10 Are there any network-accessible OpenVMS systems?

Yes, though various restrictions can and do apply.

o Hobbes
Hobbes is a MicroVAX 3100 Model 40 for which
free access and accounts are available to OpenVMS
enthusiasts. This system has BASIC, Pascal, Fortran,
and C compilers installed. If you would like an
account on Hobbes, please see the FAQ at
http://www.hobbesthevax.com/.

2-9

General Information

o OpenVMS Galaxy Test Drive
HP currently offers an OpenVMS Galaxy Test Drive
system, based on an AlphaServer 4100 series
configured as two instances of the OpenVMS
operating system. For details, please see
http://www.testdrive.compaq.com/galaxy/

o HP CSA Test Drive
http://www.testdrive.compaq.com/

o Encompasserve
telnet://eisner.decus.org/

o OpenECS
OpenECS offers free access to a VAX 6000 model 530
system. If interested, please visit:
http://vax6k.openecs.org/

__________________________________________________________
2.11 What version of OpenVMS do I need?

For information on supported platforms, please see
the OpenVMS Software Product Description (SPD) for the
particular OpenVMS version of interest.

o http://www.compaq.com/info/spd/
OpenVMS typically uses SPD 25.01.xx and/or SPD
41.87.xx.

For a table of OpenVMS versions for various platforms,
please see:

o http://www.openvms.compaq.com/openvms/supportchart.html

For information on the Multia, related Alpha
single-board computers, or other officially
unsupported systems, please see Section 14.4.1 and
Section 14.4.2.1.

The following is a rule-of-thumb for Alpha platform
support. The table Table 2-4 contains the earliest
OpenVMS Alpha release with support for a particular
series of Alpha microprocessors:

2-10

General Information

________________________________________________________________
Table 2-4 OpenVMS Alpha Version Rule-Of-Thumb

_______________________________________________________
Microprocessor General
Generation____________OpenVMS_Version_______Comments___

21064 EV4 V1.0 few
systems;
most EV4
require
later;
upgrade
available

21164 EV5 V6.2 subsequent
upgrade
available

21164A EV56 V6.2-1H3 subsequent
upgrade to
V7.1 and
later

21264 EV6 V7.1-2 subsequent
upgrade
typically
to V7.2-1
or later

21264A EV67 V7.1-2 subsequent
upgrade
typically
to V7.2-1
or later

xxxxxx EV68 V7.2-1 believed/probable;
currently
_____________________________________________________expectation

__________________________________________________________
2.12 How can I submit OpenVMS Freeware?

For the guidelines and submission info, please visit
the URL:

o http://www.openvms.compaq.com/openvms/freeware/cd_
guide.html

2-11

General Information

To order the current OpenVMS Freeware CD-ROM kit
(shipping and handling charges apply), please request
part number QA-6KZAA-H8.

__________________________________________________________
2.13 Porting applications to OpenVMS?

Porting can range from simple to rather complex, and
depends on the features used on the original platform.

This section covers generic porting, and porting from
OpenVMS VAX to OpenVMS Alpha. (Porting from OpenVMS VAX
to OpenVMS Alpha is often quite simple and involves
little more than rebuilding from source, though a
few applications using features specific to VAX will
require some additional effort to port.)

Several manuals on porting from OpenVMS VAX to OpenVMS
Alpha are available in the OpenVMS documentation set,
including information on porting VAX Macro32 assembler
code to the Macro32 compiler on OpenVMS Alpha, on
management differences, on upgrading privileged code,
and application migration:

o http://www.openvms.compaq.com:8000/

o http://www.openvms.compaq.com/doc/

o http://www.openvms.compaq.com/commercial/

Details on the C programming environment are available
at:

o http://www.openvms.compaq.com/commercial/c/c_
index.html

Details on porting VAX C to HP C are are available at:

o http://www.openvms.compaq.com/commercial/c/index_
vax.htm

An OpenVMS Porting Library is available at:

o http://www.openvms.compaq.com/ebusiness/Technology.html

2-12

General Information

Information on the Enterprise Toolkit, a Visual-based
development environment for developing applications for
OpenVMS using a Microsoft platform, is available at:

o http://www.openvms.compaq.com/commercial/et/et_
index.html

Details on DCE, CORBA, BridgeWorks, and COM/DCOM
middleware is available at:

o http://www.openvms.compaq.com/commercial/middleware.html

Information on the COE standards is available at:

o http://diicoe.disa.mil/coe/

A wide variety of programming development tools and
middleware are available as commercial products (eg:
DECset, IBM WebSphere MQ-formerly MQseries), and
various tools are also available as shareware or as
Freeware. Please see other sections of this FAQ, and
please see:

o http://www.compaq.com/csa/directory/

__________________________________________________________
2.14 What resources are available to OpenVMS software
developers?

The HP developer program DSPP is a program open to and
intended to support and to assist HP OpenVMS software
partners, consultants, and service providers:

o http://www.hp.com/dspp/

DSPP provides members with various benifits, please see
the website for details. many other benefits.

For those familiar with the program, the DIGITAL
Association of Software and Application Partners (ASAP)
program has been incorporated into the Compaq CSA
program, and CSA has subsequently been incorporated
into the HP DSPP program.

2-13

General Information

__________________________________________________________
2.15 memory management, resource management, process
scheduling, etc?

So you have been instructed to write a school research
paper on OpenVMS, and you need technical content
on the OpenVMS Virtual Memory System, on any memory
segmentation, on OpenVMS Resource Management, on the
OpenVMS File System, on the OpenVMS user interface,
etc.

Invariably, your professor/instructor/teacher will
ask you a series of questions. Most commonly, the
questions will request descriptions of one or more of
the following items, and at varying levels of detail:

o process scheduling algorithm(s)

o Interprocess comunications

o Process or system synchronization constructs

o Memory management and/or virtual memory
implementation

o RMS or XQP file structures

o Resource management

o History of HP OpenVMS

o History of Compaq and/or of Digital Equipment
Corporation (DEC)

Any particular presentation or research paper, and
particularly a scholastic presentation, can have
many different potential target audiences, and very
different presentation levels. Further, the usual
underlying reason for scholastic presentations and
scholastic research projects really has little to do
with the subject matter, it is a task specifically
intended to teach the student(s) (eg: you) how to
perform the research. The instructor already knows
most of (all of?) the information that you have been
asked to collect.

2-14

General Information

For very technical details on OpenVMS and OpenVMS
internals, the book you want is the Internals and Data
Structures Manual (IDSM), available in your school
or computing center library, and the IDSM can also be
purchased. Additional technical details of the Alpha
microprocessor are available in the Alpha Architecture
Reference Manual documentation that is available for
download. (Pointers to Alpha technical documentation
are available in Section 14.6, and elsewhere.)

For higher-level (less technical) details, the OpenVMS
documentation set is available on-line. The Programming
Concepts and the File Systems manual are probably the
best manuals to start with, depending on the particular
level of detail the research requires.

And please understand the hesitation of various folks
to provide you with a completely-written research
report on your topic. Why? We might have to work with
you after you graduate-you need to know how to perform
at least basic research on your own, regardless of the
topic.

2-15

_______________________________________________________

3 Documentation

__________________________________________________________
3.1 Where can I find online copies of OpenVMS manuals?

The HP OpenVMS and HP Layered Product documentation is
copyrighted material.

HTML format on-line product documentation sets for
specific HP OpenVMS products are presently available
at:

o http://www.openvms.compaq.com:8000/

o http://www.openvms.compaq.com/doc/

o http://www.openvms.compaq.com/commercial/

Documentation is offered on separately orderable CD-ROM
media through a subscription to the Consolidated On-
Line Documentation (ConOLD) product (see Section 2.5.)
ConOLD manuals are readable with BNU, a viewer that is
supplied with the documentation distribution. BNU can
display HTML, Bookreader, and documentation in other
formats.

MGBOOK, a viewer for Bookreader-format documentation
is available for character-cell terminals (eg. VTxxx)
via the WKU VMS Freeware file server - see question
Section 13.1 for details.

__________________________________________________________
3.2 What online information and websites are available?

On your OpenVMS system, the HELP command can provide
a wealth of information, not only on DCL commands
but on system services (HELP System_Services) and
Run-Time Library routines (HELP RTL_Routines). The
introduction displayed when you type the HELP command
with no additional keywords provides further pointers.

3-1

Documentation

OpenVMS Marketing runs a WWW server at
http://www.openvms.compaq.com/. Here, you will find
product information, strategy documents, product
roadmaps, the contents of the latest OpenVMS Freeware
CD-ROM and more.

________________________________________________________________
Table 3-1 OpenVMS Websites

_______________________________________________________
URL_______Sponsor______________________________________

http://www.openvms.compaq.com/
http://www.openvms.compaq.com/wizard/
http://www.openvms.compaq.com/wizard/wizard.zip

HP OpenVMS Marketing

http://www.openvmshobbyist.org/

Encompass DFWCUG

http://www.levitte.org/~ava/

Arne Vajh�j

http://www.saiga.com/

Saiga Systems

http://www.tachysoft.com/

Wayne Sewel

http://www.progis.de/openvms.htm

Sponsored by proGIS Software

http://www.jcameron.com/vms/

Jeff Cameron

http://seqaxp.bio.caltech.edu/www/soft_doc.html

David Mathog's (useful) information about
OpenVMS.

Cracking

http://www.vistech.net/users/beave/hack-vms-faq

"The Beave"
Includes system cracking information that can
be of interest to OpenVMS System Managers,
and to OpenVMS Network and Security Managers.

Undocumented Features

3-2

Documentation

________________________________________________________________
Table 3-1 (Cont.) OpenVMS Websites

_______________________________________________________
URL_______Sponsor______________________________________

http://www.decus.de:8080/www/vms/qaa/undoc.htmlx

DECUS Deutchland

http://www.levitte.org/~ava/vms_tip.htmlx

Arne Vajh�j

http://www.openvms.compaq.com/freeware/

The OpenVMS Freeware contains various
examples of undocumented features and
interfaces

Bibliographies

http://www.levitte.org/~ava/vms_book.htmlx

Introductory

http://www.levitte.org/~ava/vms_faq.htmlx

http://seqaxp.bio.caltech.edu/www/vms_sheet.html

http://seqaxp.bio.caltech.edu/www/vms_beginners_
faq.html

Programming

http://www.pdv-systeme.de/users/martinv/VMS_
Programming_FAQ.html

An OpenVMS Programming FAQ

Networking

http://www.tmesis.com/internet/

Tutorial information and tips for connecting
OpenVMS systems to the Internet

http://www.openvms.compaq.com/wizard/decnet/

Documentation and Specifications for DECnet
Phase IV

HP OpenVMS Documentation

http://www.openvms.compaq.com:8000/
http://www.openvms.compaq.com/doc/
http://www.openvms.compaq.com/commercial/

3-3

Documentation

________________________________________________________________
Table 3-1 (Cont.) OpenVMS Websites

_______________________________________________________
URL_______Sponsor______________________________________

Various introductory guides as well as more
advanced manuals are available in the OpenVMS
and layered product documentation set.

http://www.compaq.com/info/spd/

Software Product Descriptions (SPDs) for most
every OpenVMS-related product HP sells.

System Performance

See Section 14.2.

Patch (ECO) Kits

For the HP Services FTP server hosting
Various contract-access and non-contract
access ECO (patch) kits, see section
Section 5.16.

Catalogs and Pricing

http://www.compaq.com/products/quickspecs/productbulletin.html

HP Product QuickSpecs and product information

http://www.compaq.com/products/quickspecs/soc_
archives/SOC_Archives.html

The HP Systems and Options Catalog (SOC)
archive

http://www.businesslink.compaq.com/

Pointers to country-specific product
information, pricing, and related. The
services formerly provided by BusinessLink
are being replaced by these and other
country-specific mechanisms, please see the
URL for details.

Publications

http://www.openvms.compaq.com/openvmstimes/

The OpenVMS Times Newsletter

http://www.dfwcug.org/

The DFWCUG Quadwords Newsletter

3-4

Documentation

________________________________________________________________
Table 3-1 (Cont.) OpenVMS Websites

_______________________________________________________
URL_______Sponsor______________________________________

http://www.research.compaq.com/wrl/DECarchives/DTJ/

Back issues of the (discontinued) Digital
Technical Journal (DTJ)

http://www.compaq.com/inFORM/

The HP (Compaq) inFORM Magazine

Hardware and Software Archives

http://vax.sevensages.org/index.html

The VAXarchive, including hardware and
software information

http://www3.sympatico.ca/n.rieck/docs/alpha_diary.html

A VAX to Alpha upgrade diary

http://www.montagar.com/~patj/dec/hcps.htm

Scanned versions of old DIGITAL manuals from
DFWCUG

http://www.digital.com/lists/master-index.html

http://www.compaq.com/support/techpubs/qrg/index.html

A wide variety of HP VAX, Alpha, platform
and other product documentation. Some
___________________introductory,_some_technical.________________

__________________________________________________________
3.3 OpenVMS Product Information Telephone Numbers?

Information on HP hardware, software, products and
services is available through telephone numbers listed
in Table 3-2:

________________________________________________________________
Table 3-2 Telephone Numbers

_______________________________________________________
Telephone_________Description__________________________

1-800-AT-COMPAQ HP (Compaq, including DIGITAL and
Tandem) products and services

3-5

Documentation

________________________________________________________________
Table 3-2 (Cont.) Telephone Numbers

_______________________________________________________
Telephone_________Description__________________________

_________1-800-STORWORK____The_HP_StorageWorks_team_____________

__________________________________________________________
3.4 How do I extract the contents of a HELP topic to a text
file?

To extract all the text of a HELP topic (and its
subtopics) to a text file for perusal with a text
editor, printing out, etc., use the following command:

$ HELP/OUT=filename.txt help-topic [help-subtopic]

If the help text you want is not in the standard
help library (for example, it's help for a utility
such as MAIL that has its own help library), add
/LIBRARY=libname after the HELP verb. To see the
names of help library files, do a directory of
SYS$HELP:*.HLB.

__________________________________________________________
3.5 Does OpenVMS Marketing have an e-mail address?

Yes - if you can't get the answers to marketing
questions elsewhere, if you have comments or complaints
about OpenVMS, send mail to [email protected].
This address is not a support channel, and is solely
intended to provide informal method to communicate
directly with members of OpenVMS Marketing.

__________________________________________________________
3.6 Where can I learn about OpenVMS executive internals?

The OpenVMS Internals and Data Structure manual
(IDSM) explains how the OpenVMS executive works.
The book covers the operating system kernel: process
management; memory management; the I/O subsystem; and
the mechanisms that transfer control to, from, and
among these. It gives an overview of a particular area
of the system, followed by descriptions of the data
structures related to that area and details of the code
that implements the area.

3-6

Documentation

The first edition of the OpenVMS Alpha internals book
describes Version 1.5. Although there have been several
releases of OpenVMS Alpha since Version 1.5 (V6.1,
V6.2, V7.0, V7.1, etc) and many details in the book are
no longer accurate, it continues to provide a strong
conceptual description of OpenVMS internals.

This book has been split into five pieces, each to be
updated separately. The first such volume, published
in early 1997, was "OpenVMS Alpha Internals and
Data Structures: Scheduling and Process Control,"
which covers the Version 7.0 implementation of true
multithreading and the changed scheduling model it
implies.

The internals books are available through Digital
Press, see Section 3.7

__________________________________________________________
3.7 Where can new users find tutorial information about
OpenVMS?

First, see if your local site has information on this
topic. Each site can have site-specific features and
configuration. Some sites will have site-specific new
user's documentation, covering various site-specific
things that are difficult or impossible for the general
OpenVMS documentation to cover.

_____________________________
3.7.1 Tutorial Websites?

Various websites with OpenVMS information are
available; Table 3-3 contains some suggested URLs.

________________________________________________________________
Table 3-3 OpenVMS Tutorial Websites

_______________________________________________________
URL_______Sponsor______________________________________

Introductory

http://www.levitte.org/~ava/vms_faq.htmlx

http://seqaxp.bio.caltech.edu/www/vms_sheet.html

3-7

Documentation

________________________________________________________________
Table 3-3 (Cont.) OpenVMS Tutorial Websites

_______________________________________________________
URL_______Sponsor______________________________________

http://seqaxp.bio.caltech.edu/www/vms_beginners_
faq.html

Various introductory materials

http://www.montagar.com/openvms_class/

Members of the Encompass DFWCUG maintain
a website with many materials available,
including an Overview of OpenVMS, an
Introduction to DCL and the TPU Editor,
Advanced DCL Command Procedures, OpenVMS
Operations: Batch, Print, Tape, an
Introduction to OpenVMS Management, to
OpenVMS User Management, to OpenVMS
Network Management, and to OpenVMS Cluster
Management. These training materials have
been presented at various DECUS symposia.

HP OpenVMS Documentation

http://www.openvms.compaq.com:8000/
http://www.openvms.compaq.com/doc/
http://www.openvms.compaq.com/commercial/

Various introductory guides as well as more
advanced manuals are available in the OpenVMS
and layered product documentation set.

HP OpenVMS Training

http://www.compaq.com/training/home.html
http://www.openvms.compaq.com/wbt/index.html

HP offers training information and Technical
Resource Kits (TRKs) and other Training for
OpenVMS. An OpenVMS certification (testing)
program is also available.

http://www.jcameron.com/vms/

An OpenVMS Quiz

http://www.CCSScorp.com/

3-8

Documentation

________________________________________________________________
Table 3-3 (Cont.) OpenVMS Tutorial Websites

_______________________________________________________
URL_______Sponsor______________________________________

CCSS Interactive Learning has OpenVMS
training materials

http://www.acersoft.com/

AcerSoft Training information, and Shannon
Knows Punditry

http://www.mindiq.com/

___________________MindIQ_training_information__________________

_____________________________
3.7.2 Books and Tutorials?

Some of the OpenVMS books that are or have been
available from the Digital Press imprint

o http://www.bh.com/

are listed in Table 3-4:

________________________________________________________________
Table 3-4 DP Books

_______________________________________________________
Title_and_Author__________________________ISBN_________

Introduction to OpenVMS, 5th Edition 1 55558 194 3
Lesley Ogilvie Rice

Introduction to OpenVMS 1 878956 61 2
David W Bynon

OpenVMS Alpha Internals: Scheduling and 1 55558 156 0
Process Control

OpenVMS AXP Internals and Data 1 55558 120 X
Structures: Version 1.5

OpenVMS System Management Guide 1 55558 143 9
Richard Berry

The OpenVMS User's Guide, Second Edition 1 55558 203 6
Patrick Holmay

3-9

Documentation

________________________________________________________________
Table 3-4 (Cont.) DP Books

_______________________________________________________
Title_and_Author__________________________ISBN_________

Using DECwindows Motif for OpenVMS 1 55558 114 5
Margie Sherlock

VAX/VMS Internals and Data Structures: 1 55558 059 9
Version 5.2

Writing Real Programs in DCL, Second 1 55558 191 9
Edition
_________Hoffman_and_Anagnostopoulos____________________________

For various featured OpenVMS books, also please see:

o http://www.openvms.compaq.com/openvms/books.html

For a bibliography of various OpenVMS books, please
see:

o http://www.levitte.org/~ava/vms_book.htmlx

__________________________________________________________
3.8 What OpenVMS mailing lists are available?

Various OpenVMS mailing lists are available, with some
of the available lists detailed in Table 3-5.

________________________________________________________________
Table 3-5 OpenVMS Mailing Lists

_______________________________________________________
Subscription______________________________Interest_Area

OpenVMS Freeware archive announcement [email protected]
list
FSupdate-
[email protected][1]

_______________________________________________________
[1]This is the subscription address. Usually, you will
want to send a mail message with no subject line, and
a SUBSCRIBE or HELP command in the body of the mail
message.

3-10

Documentation

________________________________________________________________
Table 3-5 (Cont.) OpenVMS Mailing Lists

_______________________________________________________
Subscription______________________________Interest_Area

Two-way echo of vmsnet.internals VMSnet-
[email protected]

VMSnet-
Internals-
[email protected][1]

OpenVMS Alpha Internals discussions Alpha-
[email protected]

Alpha-IDS-
[email protected][1]

BLISS discussions [email protected]

BLISSters-
[email protected][1]

Process Software MultiNet mailing list Info-
(news gateway) [email protected]

Info-
MultiNet-
[email protected][1]

Process Software TCPware mailing list Info-
(news gateway) [email protected]

Info-TCPware-
[email protected][1]

Process Software PMDF mailing list (news Info-
gateway) [email protected]

Info-PMDF-
[email protected][1]

_______________________________________________________
[1]This is the subscription address. Usually, you will
want to send a mail message with no subject line, and
a SUBSCRIBE or HELP command in the body of the mail
message.

3-11

Documentation

________________________________________________________________
Table 3-5 (Cont.) OpenVMS Mailing Lists

_______________________________________________________
Subscription______________________________Interest_Area

The SRI CHARON-VAX VAX emulator package CHARON-VAX-
[email protected]

CHARON-
VAX-Users-
[email protected][1]

Info-Zip's Zip & UnZip discussion list Info-
[email protected]
Info-Zip-
[email protected][1]

RADIUS-VMS, a RADIUS server for OpenVMS radius-
discussion forum [email protected]
radius-vms-
[email protected][1]

Internet Service Providers (ISPs) vms-
running OpenVMS [email protected]
vms-isps-
[email protected][1]

Users of Mark Daniel's WASD web server http://wasd.vsm.com.au/
for OpenVMS VAX and Alpha exists.
Information about this list server and
details on how to subscribe to the list
are available at the referenced website.

VMS Forum http://www.neurophys.wisc.edu/comp/ava/vms_
forum.htmlx
_______________________________________________________
[1]This is the subscription address. Usually, you will
want to send a mail message with no subject line, and
a SUBSCRIBE or HELP command in the body of the mail
message.
________________________________________________________________

__________________________________________________________
3.9 What is this Ask The Wizard website I've heard about?

The HP OpenVMS Ask The Wizard (ATW) website is an
informal area containing questions and answers on a
wide variety of topics.

3-12

Documentation

o http://www.openvms.compaq.com/wizard/

o http://www.openvms.compaq.com/wizard/wizard.zip

For additional information, please see Section 3.9.

To access a cited topic directly, use the URL filename
WIZ_topic-number.HTML. For example, topic (1020) can be
accessed directly using the URL:

o http://www.openvms.compaq.com/wizard/wiz_1020.html

A zip archive containing all of the available topics
and questions can be downloaded from the following URL:

o http://www.openvms.compaq.com/wizard/wizard.zip

The wizard.zip zip archive is completely regenerated
when new batches of topics are posted out to the ATW
website.

Before posting a question to the Ask The Wizard
area, please read and please heed the posting rules-
and please remember to search this document, the
OpenVMS FAQ. And if you have a question that requires
an answer, or if your question has time-critical
constraints or business constraints, please contact
the HP customer support center directly.

__________________________________________________________
3.10 Access to the OpenVMS Netscape Navigator documentation?

The documentation URLs embedded into the browser itself
may not operate correctly in all cases, and (for
reasons not worthy of repeating here) redirects may
not be available.

You can manually access the documentation via:

o http://www.openvms.compaq.com:88/netscape/help/

For information on the Mozilla web browser, please see
Section 13.3.

3-13

_______________________________________________________

4 Time and Timekeeping

__________________________________________________________
4.1 UTC vs GMT vs vs UT1/UT1/UT2 TDF? What are these acronyms?

The results of an international compromise-though
some would say an international attempt to increase
confusion-UTC is refered to as "Coordinated Universal
Time" (though not as CUT) in English and as "Temps
Universel Coordinn�" (though not as TUC) in French.
(No particular information exists to explain why UTC
was chosen over the equally nonsensical TCU, according
to Ulysses T. Clockmeister, one of the diplomats that
helped establish the international compromise.)

Universal Time UT0 is solar time, UT1 is solar time
corrected for a wobble in the Earth's orbit, and UT2
is UT1 corrected for seasonal rotational variations in
rotation due to the Earth's solar orbit.

GMT-Greenwich Mean Time-is UT1. GMT is the time
at the classic site of the since-disbanded Royal
Greenwich Observatory; at the most widely-known tourist
attraction of Greenwich, England.

UTC is based on an average across multiple atomic
clocks, and is kept within 0.9 seconds of GMT, through
the insertion (or removal) of seconds. In other words,
UTC matches GMT plus or minus up to 0.9 seconds, but
UTC is not GMT.

TDF is the Timezone Differential Factor, the interval
of time between the local time and UTC. Areas that
celebrate daylight savings time (DST) will see periodic
changes to the TDF value, when the switch-over between
daylight savings time and standard time occurs.
The switch-over itself is entirely left to local
governmental folks, and can and has varied by political
entity and politics, and the switch-over has varied
over the years even at the same location.

4-1

Time and Timekeeping

If your local OpenVMS system time is off by one
hour (or whatever the local DST change) for some or
all applications, you probably need to reset your
local TDF. (For related details, please see sections
Section 4.4 and Section 10.24.1.)

Further discussions of history and politics, the Royal
Observers' outbuildings, and the compromise that left
the English with the Time Standard (the Prime Meridian)
and the French with the standards for Distance and
Weight (the Metric System) are left to other sources.
Some of these other sources include the following URLs:

o ftp://elsie.nci.nih.gov/pub/

o http://physics.nist.gov/GenInt/Time/time.html

o http://nist.time.gov/

__________________________________________________________
4.2 A brief history of OpenVMS Timekeeping, please?

Why does OpenVMS regards November 17, 1858 as the
beginning of time...

The modified Julian date adopted by the Smithsonian
Astrophysical Observatory (SAO) for satellite tracking
is Julian Day 2400000.5, which turns out to be midnight
on November 17, 1858.

SAO started tracking satellites with an 8K (nonvirtual)
36-bit IBM 704 in 1957 when Sputnik went into orbit.
The Julian day was 2435839 on January 1, 1957. This is
11225377 octal, which was too big to fit into an 18-bit
field. With only 8K of memory, the 14 bits left over by
keeping the Julian date in its own 36-bit word would
have been wasted. SAO also needed the fraction of the
current day (for which 18 bits gave enough accuracy),
so it was decided to keep the number of days in the
left 18 bits and the fraction of a day in the right 18
bits of one word.

Eighteen bits allows the truncated Julian Day (the SAO
day) to grow as large as 262143, which from November
17, 1858, allowed for 7 centuries. Possibly, the date
could only grow as large as 131071 (using 17 bits),
but this still covers 3 centuries and leaves the

4-2

Time and Timekeeping

possibility of representing negative time. The 1858
date preceded the oldest star catalogue in use at SAO,
which also avoided having to use negative time in any
of the satellite tracking calculations.

The original Julian Day (JD) is used by astronomers and
expressed in days since noon January 1, 4713 B.C. This
measure of time was introduced by Joseph Scaliger in
the 16th century. It is named in honor of his father,
Julius Caesar Scaliger (note that this Julian Day is
different from the Julian calendar that is named for
the Roman Emperor Julius Caesar!).

Why 4713 BC? Scaliger traced three time cycles and
found that they were all in the first year of their
cyle in 4713 B.C. The three cycles are 15, 19, and 28
years long. By multiplying these three numbers (15 * 19
* 28 = 7980), he was able to represent any date from
4713 B.C. through 3267 A.D.

The starting year was before any historical event known
to him. In fact, the Jewish calendar marks the start
of the world as 3761 B.C. Today his numbering scheme
is still used by astronomers to avoid the difficulties
of converting the months of different calendars in use
during different eras.

The following web sites:

o http://www.openvms.compaq.com/openvms/products/year-
2000/leap.html

o http://www.eecis.udel.edu/~ntp/

o http://www.nist.gov/

o http://www.boulder.nist.gov/timefreq/

o http://www.tondering.dk/claus/calendar.html

o http://es.rice.edu/ES/humsoc/Galileo/Things/gregorian_
calendar.html

are all good time-related resources, some general and
some specific to OpenVMS.

4-3

Time and Timekeeping

_____________________________
4.2.1__Details_of_the_OpenVMS system time-keeping?

4.2.1.1__VAX_hardware_time-keeping details...

4.2.1.1.1 TOY clock

This is battery backed up hardware timing circuitry
used to keep the correct time of year during rebooting,
power failures, and system shutdown. This clock only
keeps track of months, days, and time. The time is kept
relative to January 1st, at 00:00:00.00 of the year the
_________clock_was_initiailized.

4.2.1.1.2 EXE$GQ_SYSTIME

This is the OpenVMS VAX system time cell. This cell
contains the number of 100ns intervals since a known
reference. This cell is incremented by 100000 every
_________10ms_by_an_hardware_interval timer.

4.2.1.1.3 EXE$GQ_TODCBASE

This cell contains the time and date the system time
was last adjusted by EXE$SETTIME. It uses the same
format as EXE$GQ_SYSTIME. On adjustment of the system
time a copy of EXE$GQ_SYSTIME is stored in this cell in
both memory and on disk. This cell is used to get the
_________year_for_the_system_time.

4.2.1.1.4 EXE$GL_TODR

This cell contains the time and date the system time
was last adjusted by EXE$SETTIME. It uses the same
format as the time of year clock. On adjustment of the
system time this cell gets saved back to both memory
and disk. The contents of this cell are used to test
the validity of the TOY clock.
The system parameters SETTIME and TIMEPROMPTWAIT
determine how the system time will be set.

IF SETTIME = 0
THEN the contents of the TOY clock are compared to
those of EXE$GL_TODR. IF the TOY clock is more than
a day behind EXE$GL_TODR
THEN the TOY clock is presumed invalid.

o IF the TOY clock is within a day of EXE$GL_TODR
THEN the system time is calculated as follows:

4-4

Time and Timekeeping

o EXE$GQ_SYSTIME = EXE$GQ_TODCBASE + ((TOY_CLOCK -
EXE$GL_TODR) * 100000)

o IF SETTIME = 1 or the TOY clock is invalid
THEN the value of TIMEPROMPTWAIT determines how to
reset the time of year. IF TIMEPROMPTWAIT > 0
THEN the user is prompted for the time and date,
for a length of time equal to TIMEPROMPTWAIT
microfortnights.

o IF TIMEPROMPTWAIT = 0
THEN the time of year is the value of EXE$GL_TODR
+ 10ms.

o IF TIMEPROMPTWAIT < 0
to proceed until they do so.

o THEN the user is prompted for the time and date
and unable

When booting a CD-ROM containing an OpenVMS VAX system,
the system will typically be deliberately configured
prompt the user to input the time - this is necessary
in order to boot with the correct time.

If either TIMEPROMPTWAIT or SETTIME are set to zero,
OpenVMS VAX will use the TOY clock to get the time of
year, and the year will be fetched from the CD-ROM.
The value of the year on the CD-ROM media (saved within
the SYS.EXE image) will most likely be that of when
the CD-ROM was made, and cannot be changed. Unless the
current year happens to be the same year as that on
the CD-ROM, most likely the year will be off. (Further,
with the calculation of Leap Year also being dependent
on the current year, there is a possibility that the
date could be off too.)

_____________________________
4.2.1.2 Alpha hardware time-keeping details...

4-5

Time and Timekeeping

_____________________________
4.2.1.2.1 Battery-Backed Watch (BB_WATCH) Chip

This is battery backed up hardware timing circuitry
used to keep the correct time of year during rebooting,
power failures, and system shutdown. This clock keeps
_________track_of_date_and_time in 24 hour binary format.

4.2.1.2.2 EXE$GQ_SYSTIME

This is the OpenVMS Alpha system time cell. This cell
contains the number of 100ns intervals since November
17, 1858 00:00:00.00. This cell is incremented by
_________100000_every_10ms_by an hardware interval timer.

4.2.1.2.3 EXE$GQ_SAVED_HWCLOCK

This cell is used by OpenVMS Alpha to keep track of the
last time and date that EXE$GQ_SYSTIME was adjusted. It
keeps the same time format as EXE$GQ_SYSTIME. The value
in this cell gets updated in memory and on disk, every
time EXE$GQ_SYSTIME gets adjusted.

o The system parameters SETTIME and TIMEPROMPTWAIT
determine how the system time will be set.

o If SETTIME = 0 then EXE$INIT_HWCLOCK reads the
hardware clock to set the system time.

o IF TIMEPROMPTWAIT > 0
THEN the value of TIMEPROMPTWAIT determines how
long the user is prompted to enter the time
and date. If time expires and no time has been
entered the system acts as if TIMEPROMPTWAIT = 0.

o IF TIMEPROMPTWAIT = 0
THEN the system time is calculated from the
contents of EXE$GQ_SAVED_HWCLOCK + 1.

o IF TIMEPROMPTWAIT < 0
THEN the user is prompted for the time and date
and unable to continue until the information is
entered.

Unlike the VAX, the Alpha hardware clock tracks the full date
and time, not just the time of year. This means it is possible
to boot from the CD-ROM media without entering the time at the
CD-ROM bootstrap. (This provided that the time and date have
been initialized, of course.)

4-6

Time and Timekeeping

IA-64 (Itanium) hardware time-keeping details to be
added...

_____________________________
4.2.1.3 Why does VAX need a SET TIME at least once a year?

Because the VAX Time Of Year (TOY) has a resolution of
497 days, the VAX system time is stored using both
the TOY and the OpenVMS VAX system image SYS.EXE.
Because of the use of the combination of the TOY and
SYS.EXE, you need to issue a SET TIME command (with
no parameters) at least once between January 1st and
about April 11th of each year, and whenever you change
system images (due to booting another OpenVMS VAX
system, booting the standalone BACKUP image, an ECO
that replaces SYS.EXE, etc).

The SET TIME command is automatically issued during
various standard OpenVMS procedures such as SHUTDOWN,
and it can also obviously be issued directly by a
suitably privileged user. Issuing the SET TIME command
resets the value stored in the TOY, and (if necessary)
also updates the portion of the time (the current year)
saved in the SYS.EXE system image.

This VAX TOY limit is the reason why OpenVMS VAX
installation kits and standalone BACKUP explicitly
prompt for the time during bootstrap, and why the time
value can "get weird" if the system crashes outside the
497 day window (if no SET TIME was issued to update the
saved values), and why the time value can "get weird"
if a different SYS$SYSTEM:SYS.EXE is used (alternate
system disk, standalone BACKUP, etc).

_____________________________
4.2.2 How does OpenVMS VAX maintain system time?

VAX systems maintain an interval clock, and a hardware
clock.

The VAX hardware clock is called the TOY ("Time Of
Year") clock. The register associated with the clock is
called the TODR ("Time Of Day Register").

4-7

Time and Timekeeping

The TOY clock-as used-stores time relative to January
first of the current year, starting at at 00:00:00.00.
It is a 100 Hz, 32-bit counter, incremented every 10ms,
and thus has a capacity of circa 497 days.

OpenVMS (on the VAX platform) stores system date
information-and in particular, the current year-in
the system image, SYS$SYSTEM:SYS.EXE.

The TOY is used, in conjunction with the base date
that is stored and retrieved from the system image, to
initialize the interval clock value that is stored in
EXE$GQ_SYSTIME.

Once the interval clock is loaded, the system does
not typically reference the TOY again, unless a SET
TIME (with no parameters) is issued. The interval
clock value is updated by a periodic IPL22 or IPL24
(depending on the specific implementation) interrupt.
(When these interrupts are blocked as a result of the
activity of higher-IPL code-such as extensive driver
interrupt activity or a hardware error or a correctable
(soft) memory error-the clock will "loose" time, and
the time value reported to the user with appear to have
slowed down.)

On most (all?) VAX systems, the battery that is
associated with the TOY clock can be disconnected and
replaced if (when) it fails-TOY clock failures are
quite commonly caused by a failed nickel-cadmium (NiCd)
or lithium battery, or by a failed Dallas chip.

__________________________________________________________
4.3 Keeping the OpenVMS system time synchronized?

To help keep more accurate system time or to keep
your system clocks synchronized, TCP/IP Services NTP,
DECnet-Plus DECdtss, DCE DTSS, and other techniques
are commonly used. If you do not have IP access to a
time-base, then you could use dial-up access to NIST or
other authoritative site.

There exists code around that processes the digital
(ie: binary) format time that is available via a
modem call into the NIST clock (the Automated Computer
Telephone Service (ACTS)), and code that grabs the

4-8

Time and Timekeeping

time off a GPS receiver digital link, or a receiver
(effectively a radio and a codec) that processes
the time signals from radio station WWV, WWVH, WWVB,
or similar. (Processing these time protocols often
involves little more than reading from an EIA232
(RS232) serial line from the receiver, something that
is possible from most any language as well as directly
from DCL.)

One example of acquring a time-base involves the
IRIG time format (IRIG-A, -B, -G), a binary signal
containing the current time in hours, minutes, seconds
and days since the start of the current year. IRIG
can also contain the time of day as the number of
seconds since midnight. HP Custom Systems and third-
party vendors offer various IRIG-based reader/generator
modules for OpenVMS systems.

Differing time servers (DECnet-Plus DTSS, DCE
DTSS, NTP, etc) do not coexist particularly well,
particularly if you try to use all these together
on the same node. Please pick and use just one. (If
needed, you can sometimes configure one package to
acquire its timebase from another protocol, but one
and only one time server package should have direct
control over the management of and drifting of the
local OpenVMS system time. In the specific case of
DECnet-Plus DTSS, older product versions and versions
V7.3 and later provide a provider module, a module
which permits DTSS to acquire its time from NTP. For
details on this, please see the comments in the module
DTSS$NTP_PROVIDER.C.)

Useful URLs:

o http://www.boulder.nist.gov/timefreq/service/nts.htm

o http://www.boulder.nist.gov/timefreq/service/acts.htm

o http://www.boulder.nist.gov/timefreq/

o http://www.time.gov/

4-9

Time and Timekeeping

_____________________________
4.3.1 Why does my OpenVMS system time drift?

Memory errors, hardware problems, or most anything
operating at or above IPL 22 or IPL 24 (clock IPL is
system family dependent; code executing at or above
the clock IPL will block the processing of clock
interrupts), can cause the loss of system time. Clock
drift can also be caused by normal (thermal) clock
variations and even by the expected level of clock
drift.

When clock interrupts are blocked as a result of the
activity of high-IPL code-such as extensive driver
interrupt activity or a hardware error or a correctable
(soft) memory error-the clock will "loose" time, and
the time value reported to the user with appear to have
slowed down. Correctable memory errors can be a common
cause of system time loss, in other words.

Clock drift can also be (deliberately) caused by the
activity of the DTSS or NTP packages.

Also see Section 14.8, Section 14.15, and
Section 4.3.2.

_____________________________
4.3.2 How can I drift the OpenVMS system time?

With DECdts and TCP/IP Services NTP, the system time
value is "drifted" (rather than changed), to avoid the
obvious problems that would arise with "negative time
changes". The same basic clock drifting technique is
used by most (all?) time servers operating on OpenVMS,
typically using the support for this provided directly
within OpenVMS.

An example of the technique used (on OpenVMS VAX)
to drift the system time is the SETCLOCK tool on the
OpenVMS Freeware.

For information on the use of the EXE$GL_TIMEADJUST and
EXE$GL_TICKLENGTH cells on OpenVMS Alpha, see OpenVMS
AXP Internal and Data Structures, located on page 348.

4-10

Time and Timekeeping

For those areas which switch between daylight savings
time (DST) and standard time, the time value is not
drifted. The time is adjusted by the entire interval.
This procedure is inherent in the definition of the
switch between DST and standard time.

_____________________________
4.3.3 How can I configure TCP/IP Services NTP as a time
provider?

An NTP time provider provides its idea of the current
time to NTP clients via the NTP protocol. Most systems
are NTP clients, but...

NTP has a heirarchy of layers, called strata. The
further away from the actual NTP time source (Internet
time servers are at stratum 1), the lower the strata
(and the larger the number assigned the statum).

NTP explicity configured at stratum one provides time
to NTP operating at lower strata, and the provided time
is acquired based on the local system time or via some
locally-accessible external time source.

NTP at other (lower) strata both receive time from
higher strata and can provide time to lower strata,
and automatically adjust the local stratum. The highest
stratum is one, and the lowest available stratum is
fifteen.

The TCP/IP Services NTP package can operate at any
stratum, and can be configured as a peer, as a client,
or as a broadcast server. NTP can also provide time to
a DECnet-Plus DTSS network, see Section 4.3.

With TCP/IP Services V5.0 and later, the only supported
reference clock is the LCL (local system clock). If
your system has an excellent clock or if the system
time is being controlled by some other time service
or peripheral (such as DTSS services, GPS services,
a cesium clock, a GPIB controller or other similar
time-related peripheral), you can configure NTP to use
the system clock as its reference source. This will
mimic the master-clock functionality, and will configre
NTP as a stratum 1 time server. To do this, enter the
following commands in TCPIP$NTP.CONF:

4-11

Time and Timekeeping

server 127.127.1.0 prefer
fudge 127.127.1.0 stratum 0

For local-master functionality, the commands are very
similiar. Use:

server 127.127.1.0
fudge 127.127.1.0 stratum 8

The difference between these two is the stratum, and
the omission of the prefer keyword. Specifying a higher
stratum allows the node to act as a backup NTP server,
or potentially as the sole time server on an isolated
network. The server will become active only when all
other normal synchronization sources are unavailable.
The use of "prefer" causes NTP to always use the
specified clock as the time synchronization source.

With the TCP/IP Services versions prior to V5.0,
the NTP management is rather more primitive. To
configure the local OpenVMS system from an NTP
client to an NTP server (on TCP/IP Services versions
prior to V5.0), add the following line to the
sys$specific:[ucx$ntp]ucx$ntp.conf file:

master-clock 1

Also, for TCP/IP Services prior to V5.0, see the NTP
template file:

SYS$SPECIFIC:[UCX$NTP]UCX$NTP.TEMPLATE

Note that NTP does not provide for a Daylight Savings
Time (DST) switch-over, that switch must arise from
the timezone rules on the local system and/or from the
SYS$EXAMPLES:DAYLIGHT_SAVINGS procedure. (Further,
there is a known bug in SYS$EXAMPLES:DAYLIGHT_
SAVINGS.COM in V7.3, please obtain the available ECO
kit.)

For current TCP/IP Services and related OpenVMS
documentation, please see:

o http://www.openvms.compaq.com:8000/

o http://www.openvms.compaq.com/doc/

o http://www.openvms.compaq.com/commercial/

4-12

---------------------------- #include <rtfaq.h> -----------------------------
For additional, please see the OpenVMS FAQ -- www.hp.com/go/openvms/faq
--------------------------- pure personal opinion ---------------------------
Hoff (Stephen) Hoffman OpenVMS Engineering hoff[at]hp.com