Updates for VM/XA SP CMS 5.5 (1989-1990)
Using CMS 5.5 and VM/XA SP (5 May 1989)
CMS 5.5 is a significantly new and different CMS. There are new commands
and new options, but the biggest changes are internal and aren't
The traditional 370 architecture allowed only 24 bits for storage
addressing, limiting programs to a 16 megabyte address space. The new
extended architecture (XA) uses 31 bits for storage addressing,
providing a potential for billions of bytes of addressability. (Note that
VM/XA SP has an implementation limit of 999 megabytes and each userid has
an assigned limit which generally is lower still.) In addition to this,
XA introduces many other changes, most significantly in the input/output
system and the format and use of reserved storage locations, control
registers, and status indications.
VM/XA SP Release 2
VM/XA SP makes the new features of XA available to CMS and programs
running under it. XA SP supports two modes of virtual machine operation:
370 and XA. In 370 mode (the initial setting at logon) the old 370
architecture and its constraints obtain. This has the benefit of
increasing compatibility with previous releases of VM, but restricts
programs to 16 megabytes. In XA mode all of the new features of XA are
used, but at the cost of compatibility. The important point to remember
here is that if you don't need a larger virtual machine you should keep
below 16 megabytes and run in 370 mode to minimize your difficulties
during conversion. The STORAGE command automatically handles mode
switching as necessary based on your machine size.
VM/XA SP introduces a number of other changes that are unrelated to the
new architecture. Changes in the spool system are perhaps the most
obvious. There have been changes in the syntax of some commands and in
the formats of many messages.
VM/XA SP does not yet provide all of features of earlier, non-XA versions
CMS uses the address space from about 12 megabytes to 16 megabytes for
its nucleus, disk directories, and shared code. This is true regardless
of the size of your virtual machine. Thus a 12 megabyte machine provides
about the same amount of space for user programs and data as a 16
megabyte machine. The initial storage size for most users at logon is 2
The current VS FORTRAN (2.3) is supported under XA SP. Large arrays that
will extended above the 16 megabyte boundary must be declared in dynamic
common. If these arrays are passed through to subroutines through the
calling sequences then only the calling program needs to declare them as
In general, IBM-supplied commands work in all modes. Most other commands
work in 370 mode (16 megabytes or less), but may not in XA mode (greater
than 16 megabytes). Commands that haven't been converted will often fail
with "operation exception" or "specification exception" errors. The
chart below lists the status of some often-used commands.
Some of these commands are used by other commands. Many other commands,
for example, depend on MENUEXEC for display management and are therefore
not XA capable either.
The following lists the status of the commands that are not supplied by
IBM as a part of CMS (most were written here, at other universities, or
are from non-IBM commercial sources). XA indicates that a command can
be used in an XA-mode machine, 370 indicates that a 370-mode machine is
required, No indicates that it is not available under VM/XA SP, and ?
indicates a command that hasn't been tested.
A-DISK XA HASM XA RAP No
ACCEPT XA I-DEAS No RATES No
Ada (IBM) 370 IEFBR14 XA RBROWSE 370
APRINT 370 INPUT XA RDRCOST ?
ASMXC XA INSTNAME XA REPRINT ?
ASMXCG XA IUCVTRAP 370 RESTART XA
ASMXG XA JES XA RESTORE See PRESERVE
AUTOLINK XA JOBS XA RETCODE XA
BALANCE No JULIAN XA REXXCALL XA
BASIC (OS) No KERMIT No REXXDUMP XA
BASIC (VS) 370 LABELS ? RSCAN ?
BATCH (New) XA LEDIT 370 RUNID ?
BATCHSYS XA Librarian ? RXEDIT ?
BIGFILES XA LINEMODE 370 RXUNPACK ?
BROWSE XA LINKS XA SADT ?
BURN XA LISP ? SCAN ?
C (IBM) XA Lisp (IBM) XA Scratchpad 370
CADAM No LISTX 370 SCRIPT 370
CALC XA LOOK XA SEARCH 370
CALENDAR 370 LWBADGE ? SELECT 370
CANCEL XA LWDEST XA SENDGATE ?
CASE XA LWGDDM 370 SESSION 370
CATIA No LWNAMES XA SET7171 370
CBDS No LWPLOT 370 SHIP XA
CC No LWPRINT XA Simscript ?
CHECKBUF XA LWSCRIPT ? SLFTEACH ?
CJSPREP ? MAIL XA SORTF 370
CLRSCRN XA MAILBOOK XA SPACE XA
CMSCMSG No MAILCHEC XA SPELL 370
CMSDIO No MANUAL 370 SPELLCHK 370
CMSEMSG No MATCH XA SPELLDEF 370
CMSPMSG No MATLAB ? SPELLFIX 370
CMSPRT No MAXSTOR No SPELLLEX 370
CMSPUN No MENUEXEC See Xmenu SPITBOL ?
CMSRAP No MODULE XA SPITLOAD ?
CMSREAD No NAMES XA SPLPREP XA
CMSTIO XA NAMESORT XA SSORT See SyncSort
COBOL (Debug) ? NETCHECK XA SSORTF See SyncSort
COBOL (VS) ? NETCMD XA STATUS XA
CODETRAN XA NETNODE XA STK XA
COST No NETSTAT 370 STKCP XA
DELETE XA NEWFILES ? STKDATE XA
DI-3000 370 NEWS 370 STKDISK XA
DISKSIZE XA NICK XA STKFILE XA
DMS ? OPTIONS 370 STKID XA
DMSCVT 370 OUTPUT XA STKRDR XA
DOWNLOAD ? PACK XA STKTERM XA
DRONE XA PAINTSHO 370 STKTIME XA
DROP XA PANEL See DMS STKXRDR XA
ENVIRON XA Pascal (P4) ? STORAGE XA
EUDCMSX See DMS Pascal (VS) XA SUBMIT (CMS) See BATCH
EXPLAIN No Pascal (8000) ? SUBMIT (MVS) XA
FFS 370 PASSWORD XA SUGGEST XA
FILESIZE XA PATH 370 SyncSort 370
FINDJOB XA PCTRANS ? SYSID XA
FINDPRT XA PHASE XA TapeMap XA
FLIST XA PHONE XA TDISK XA
FORTRAN (VS) XA PHONEPRT XA TELL XA
FORTRAN Debug ? PICSURE 370 TELNET 370
FORTRAN G ? PING 370 TERMINFO XA
FORTRAN HX ? PLC ? TESTCOB ?
FPRINT XA PLOGOFF XA TKPLOT ?
FREE XA PLOT ? TPRINT XA
FSEND ? PLOTLW 370 UNPACK XA
FTP 370 PLOTTEK 370 UPLOAD ?
GATHER See REPRINT PRESERVE XA VERIFY XA
GDDM 370 Prolog (IBM) 370 VIEW 370
GETFMODE XA PSEDIT 370 WAITRDR XA
GETVADDR XA PUBLIC XA WHOIS XA
GK-2000 370 PVM 370 XMENU 370
GRAB XA QON XA YCALC 370
Graphigs 370 QSF ?
GRIPE XA RANDOM XA