Filter
Top Products
When this program received control from MVS
Reg. 13 contained address of MVS save area.
Reg. 14 contained address of MVS return.
Reg. 15 contained address of this program′s entry point.
PROGA START
SAVE (14,12),,* Store Regs in MVS save area
+ B 10(,15)
+ DC AL1(5)
+ DC CL5′ PROGA′
+ STM 14,12,12(13)
LR 12,15 Load start address in Reg 12
USING PROGA,12 Define Reg 12 as base reg
ST 13,SAVEIT+4 Store address of MVS save
* area in PROGA′ s save area
LA 11,SAVEIT Load address of this Program
* save area into Reg 11
ST 11,8(13) Store address of PROGA′ s save
* area in MVS save area
LR 13,11 Load Reg 13 to point to this
.
APPLICATION PROGRAMMER LOGIC
.
L 13,SAVEIT+4 Load address of MVS save area
* into Reg 13
RETURN (14,12),RC=0 Restore registers and branch
* to MVS Return Address
+ L 14,12(,13) Restore Register 14
+ LA 15,0 Load Return Code
+ LM 0,12,20(13) Restore the registers
+ BR 14 Return
SAVEIT DC 18F′0′
Figure 29. Sample Initiation Termination Coding
13.2.1.3 Communication Region
VSE has a communication region, a storage area within the supervisor, that
contains:
•
The date
•
The job name
•
User program communication bytes
•
User program switch indicators (UPSI)
•
Problem program area addresses.
MVS does not provide a similar fixed area in the control program. Some of the
VSE communication region facilities are available in MVS as explained in the
following text.
Date
The VSE macro instruction COMRG provides the address of the communication
274 VSE to OS/390 Migration Workbook