IBM System/360 System Programmer's Guide

volume pointer consists of a 4-tyte device code, a 6-byte volume serial
number, and a 2-byte data set sequence number. The sequence number is
always zero for direct-access volurres. (Device codes are contained in
Appendix B of this chapter.)
Volumes are processed in the order that they appear in the volume
list. Those volunles that are pointed to at the beginning of the list
are processed first. If a volume is not mounted, a rressage is issued to
the operator requesting him to mount the voluroe. You can indicate the
I/O device on which unmounted volumes are to be mounted by loading
register 0 with the address of the UCB associated with the device to be
used. When the volume is mounted, processing continues. If you do not
load register 0 with a UCB address, its contents rrust be zero.
If the operator cannot mount the requested volume, he issues a reply
indicating that he cannot fulfill the request. A condition code is then
set in the last byte of the volume pointer for the unavailable volume,
and the next volume indicated in the volume list is processed or
requested.
Example:
volumes.
In the following example, data set A.B.C is deleted from two
The expiration date in the format 1 DSCB is ignored.
r---------T----------T-------------------------------------------------,
I Name I Operation I Operand I
~---------+----------+-------------------------------------------------~
DELABC
DSABC
VOLIST
SR
I 0,0 SET REG 0 TO ZEROI
SCRATCH I DELABC DELETE DATA SET I
Check Exceptional Returns A.B.C. FROM TWO I
CAMLST I SCRATCH,DSABC"VOLIST"OVRD VOLUMES, IGNORING I
DC I CL44' A. B. C' THE EXPIRATION I
DC I B'2' DATE IN THE DSCB. I
DC I X'30002001' 2311 DISK STORAGE I
DC I CL6'000017' VOLUME SERIAL NO. I
DC I H'O' SEQUENCE NUMEER I
DC I X'30002001' 2311 DISK STORAGE I
DC I CL6' 000018' VOLUME SERIAL NO. I
DC I H'O' SEQUENCE NUMBER I
L _________ ~ __________ ~ _________________________________________________ J
The SCRATCH macro-instructicn points to the CAMLST macro-instruction.
SCRATCH, the first operand of CAMLST, specifies that a data set be
deleted. DSABC, the second operand, specifies the main storage location
of a 44-nyte area into which you have placed the fully qualified name of
the data set to be deleted. VOLIST, the fourth operand, specifies the
main storage location of the volunie list you have built. OVRD, the
sixth operand, specifies that the expiration date be ignored in the OSCB
of the data set to be deleted.
HOW TO RENAME A DATA SET
You rename a data set stored on direct-access volumes by using the
RENAME and CAMLST macro-instructions. This causes the data set nanie in
all format 1 data set control blocks (DSCB) for the data set to be
replaced by the new narre that you supply_
If a data set to be renanled is stored on more than one volume, either
a device must be available on which to mount the volumes, or at least
one volume must be mounted. In addition, all other required volumes
must be serially mountable. Certain volumes, such as the system
residence volume, must always be mounted.
When renaming a data set, you must build a complete volume list in
main storage. This volun'e list consists of volume pointers for all
20

IBM System/360 Specifications

General

Brand	IBM
Model	System/360
Category	Desktop
Language	English