=:The OpenVMS Frequently Asked Questions(FAQ)C

The OpenVMS Frequently Asked Questions(FAQ)


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Chapter 12
Miscellaneous Information

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12.1 Where can I find information on escape and control sequences?



@Information on escape and control sequences can be found in the DOpenVMS I/O User's Reference Manual, in the chapter on the Bterminal driver. The chapter also includes details on the general &format and content of these sequences.

DSpecific details on the escape and control sequences supported by a Bparticular serial device are typically found in the documentation @provided with the specific device. Information on the sequences Fsupported by DECwindows DECterm terminal emulator are included in the DECwindows documentation.

GExamples of common escape and control sequences---those typically used Gby the OpenVMS screen management package---can be found in the OpenVMS $system file SYS$SYSTEM:SMGTERMS.TXT.

EThe following refers to the function keys on the LK-series keyboards Ffound on the VT-series terminals such as the VT220 and VT510, and the ?LK-series keyboards found on the OpenVMS workstations, and the Hkeyboards found on compatible terminals. (Though note that the keyboard @itself does not generate the sequence, the terminal or Hterminal emulator generates the sequence in response to user input.) In Dthe following, {CSI} is decimal code 155 and can be replaced by the Bsequence "{ESC}[" (without the quotes) particularly for seven-bit Doperations, SS3 is decimal code 143 and can be replaced by "{ESC}O" Hparticularly for seven-bit operations. Older VT1xx series terminals and Fany other terminals operating with seven-bit characters should not be 1sent eight-bit operators such as {CSI} and {SS3}.

 

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,PF1={SS3}P PF2={SS3}Q PF3={SS3}R PF4={SS3}S BKP0={SS3}p KP1={SS3}q KP2={SS3}r KP3={SS3}s KP4={SS3}t KP5={SS3}u JKP6={SS3}v KP7={SS3}w KP8={SS3}x KP9={SS3}y KPCOMMA={SS3}l KPMINUS={SS3}m JKPPERIOD={SS3}n ENTER={SS3}M DNARROW={CSI}B UPARROW={CSI}A LFARROW={CSI}D IRTARROW={CSI}C FIND={CSI}1~ INSERT={CSI}2~ REMOVE={CSI}3~ SELECT={CSI}4~ JPREV={CSI}5~ NEXT={CSI}6~ F6={CSI}17~ F7={CSI}18~ F8={CSI}19~ F9={CSI}20~ AF10={CSI}21~ F11={CSI}23~ F12={CSI}24~ F13={CSI}25~ F14={CSI}26~ NHELP={CSI}28~ DO={CSI}29~ F17={CSI}31~ F18={CSI}32~ F19={CSI}33~ F20={CSI}34~ 



=An example of working with escape sequences (in DCL) follows:

 

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$ esc5m = "*[5m" $ esc5m[0,8] = 27 $ esc0m = "*[0m" $ esc0m[0,8] = 27 3$ write sys$output esc5m + "blinking text" + esc0m 



BDocumentation on an ANSI terminal relatively similar to the VT525 series is available at:



<Also see the various documentation and manuals available at:



@Information on the ReGIS graphics character set is available at:



Also:



lAlso see Section 11.6, Section 8.11.s

12.2 Does DECprint (DCPS) work with the LRA0 parallel port?



HThe parallel printing port LRA0: found on many OpenVMS Alpha systems is Dcapable of some bidirectional communications, with enough for basic 'operations with most parallel printers.

HDECprint (DCPS) requires more than just the simple handshaking provided Dby the LRA0: port, therefore DCPS does not work with the LRA0: port.n

12.3 How do I check for free space on a (BACKUP) tape?



CYou cannot know for certain, though you can certainly estimate the remaining capacity.

CTape media is different than disk media, as disks have a known and Bpre-determined fixed capacity. Modern disks also appear logically Eperfect, based on bad block revectoring support and the extra blocks Bhidden within the disk structure for these bad block replacements.

DThe capacity of tape media is not nearly as pre-determined, and the Hcapacity can vary across different tape media (slightly different media Elengths or different foil markers or other variations, for instance) Hand even on the same media over time (as bad spots in the media arise). HTapes can vary the amount of recording media required, depending on the =remaining length of the tape, the numbers of correctable and Funcorrectable media errors that might occur, the numbers and sizes of ?the inter-record gaps and related tape structure overhead, the >particular media error recovery chosen, the tape density, the Eefficiently of any data compression in use, and the storage overhead 4required by BACKUP, tar, and other similar commands.

DBACKUP using with the default settings results in approximately 15% Foverhead, in terms of saveset size. (eg: Assuming a 500 KB input, the total size would be 575 KB.)

Assuming no compression:
. 4 GB media / 575 KB saveset = 7294 savesets

Assuming 1:2 compression:
,8 GB media / 575 KB saveset = 14588 savesets



/  
Note
DThere are no inter-record gaps on DAT tapes. When determining media Hcapacity, you have to consider these gaps with nine-track magtape media Eand other formats with gaps. This is not the case with DAT (DDS), as ?the format has no recording gaps. However, the block structure Dunderneath the variable length record recording is based on a block Fsize of circa 124 KB. Further, writing doubles filemarks and such can Hcause a loss of up to the underlying block size. Thus even though there Care no inter-record gaps on DAT, larger savesets are still usually best.


EThe compression algorithms used on various devices are generally not Fdocumented---further, there is no way to calculate the effective data Fcompression ratio, the tape mark overhead, and similar given just the Cdata to be stored on tape---short of actually trying it, of course.

DA typical compression ratio found with "everyday" data is somewhere around 1:1.8 to 1:2.



/  
Note
FOpenVMS often uses the term COMPACTION for compression control, as in /the qualifier /MEDIA_FORMAT=COMPACTION.
]

12.4 So what happened to sys$cmsuper?



There is no SYS$CMSUPR service.

FThe typical wisdom for getting into supervisor access mode (from user ?mode) is to execute a routine in executive mode (via a call to FSYS$CMEXEC and the appropriate privilege) and then issue a SYS$DCLAST Gwith the ASTADR parameter pointing to your routine entry point and the *ACMODE parameter specified as PSL$C_SUPER.

DAlternatively, you can reset mode in the call stack return path and 9unwind from executive or kernel out into supervisor mode.b

12.5 Correctly using license PAKs and LMF?



HIf you have multiple LMF$LICENSE.LDB databases in your OpenVMS Cluster, Dthen each and every PAK must be installed in each and every license Ddatabase present in an OpenVMS Cluster. Even if you use /EXCLUDE or F/INCLUDE, you need to have a consistent set of PAKs registered across 7all licensing databases present in the OpenVMS Cluster.

CIf your software license permits it, you can use the following two "commands to transfer license PAKs:

 

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$ LICENSE COPY... 2$ LICENSE ISSUE/PROCEDURE/OUTPUT=file product,... 



HTo display the particular license(s) required (such as when you receive 3a NOLICENSE error), use the following DCL sequence:

 

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$ SET PROCESS/PRIVILEGE=ALL $ REPLY/ENABLE 4$ DEFINE/SYSTEM/EXECUTIVE LMF$DISPLAY_OPCOM_MESSAGE 



DThis logical name will cause all license failures to generate OPCOM Dmessages, and this will hopefully show which license(s) you need--- Athere may well also be additional license failures displayed, as Fvarious products can check for and can be enabled by multiple license <PAKs. You will want to deassign this logical name when done.

%Some of the more common license PAKs:

 

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C  DECnet Phase IV:   DVNETRTG, DVNETEND, DVNETEXT, or NET-APP-SUP* C  DECnet-Plus:       DVNETRTG, DVNETEND, DVNETEXT, or NET-APP-SUP* *  TCP/IP Services:   UCX, or NET-APP-SUP* :  OpenVMS Alpha:     OPENVMS-ALPHA and OPENVMS-ALPHA-USER   OpenVMS VAX:       VAX-VMS $  OpenVMS Galaxy:    OPENVMS-GALAXY .  Cluster (Alpha):   VMSCLUSTER, NET-APP-SUP* .  Cluster (VAX):     VAXCLUSTER, NET-APP-SUP* 



DVarious NET-APP-SUP (NAS) license packages are available, each with Bdiffering collections of products authorized. See the various NAS BSoftware Product Description (SPD) documents for specific details.



GTo determine which license PAK is failing (via a license check failure OPCOM message), use the command:

 

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9$ DEFINE/SYSTEM/EXECUTIVE LMF$DISPLAY_OPCOM_MESSAGE TRUE 



GRealize that defining this logical name will cause license checks that Hare otherwise hidden (unimplemented, latent, or part of a check for any Fof a series of licenses) to become visible. In other words, expect to ;see some spurious license check calls when you define this.

EFor information on PAKGEN and on generating license PAKs, please see iSection 10.10. For information on obtaining commercial and hobbyist Flicenses, and for additional adminstrative information on LMF, please ksee Section 2.8.4 and Section 2.8.1.

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Chapter 13
Finding and using Software

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13.1 Where can I find freeware/shareware/software for OpenVMS?