The disassembly view
When you debug a program through the disassembly view, the Source window displays the disassembly instructions. The language area of the z/OS® Debugger screen (upper left corner) displays the word Disassem. The z/OS Debugger screen appears as follows:
Disassem LOCATION: MAIN initialization
Command ===> Scroll ===> PAGE
MONITOR --+----1----+----2----+----3----+----4----+----5----+----6 LINE: 0 OF 0
******************************* TOP OF MONITOR ********************************
****************************** BOTTOM OF MONITOR ******************************
SOURCE: MAIN +----1----+----2----+----3----+----4----+----5----+ LINE: 1 OF 160
0 1950C770 47F0 F014 BC 15,20(,R15) .
A 4 1950C774 00C3 ???? .
6 1950C776 B C5C5 ???? .
8 1950C778 0000 ???? .
A 1950C77A 0080 C ???? .
C 1950C77C 0000 ???? .
E 1950C77E 00C4 ???? D .
10 1950C780 47F0 F001 BC 15,1(,R15) .
14 1950C784 90EC D00C STM R14,R12,12(R13) .
18 1950C788 18BF LR R11,R15 E .
1A 1950C78A 5820 B130 L R2,304(,R11) .
1E 1950C78E 58F0 B134 L R15,308(,R11) .
22 1950C792 05EF BALR R14,R15 .
24 1950C794 1821 LR R2,R1 .
26 1950C796 58E0 C2F0 L R14,752(,R12) .
2A 1950C79A 9680 E008 OI 8(R14),128 .
2E 1950C79E 05B0 BALR R11,0 .
LOG 0----+----1----+----2----+----3----+----4----+----5----+----6- LINE: 1 OF 5
********************************* TOP OF LOG **********************************
IBM z/OS Debugger 16.0.n
08/04/2022 03:55:40 AM
5724-T07: Copyright IBM Corp. 1992, 2023
0004 EQA1872E An error occurred while opening file: INSPPREF. The file may not
0005 exist, or is not accessible.
0006 SET DISASSEMBLY ON ;
PF 1:? 2:STEP 3:QUIT 4:LIST 5:FIND 6:AT/CLEAR
PF 7:UP 8:DOWN 9:GO 10:ZOOM 11:ZOOM LOG 12:RETRIEVE- A Prefix Area
- Displays the offset from the start of the CU or CSECT.
- B Columns 1-8
- Displays the address of the machine instruction in memory.
- C Columns 13-26
- Displays the machine instruction in memory.
- D Columns 29-32
- Displays the op-code mnemonic or
????if the op-code is not valid. - E Columns 35-70
- Displays the disassembled machine instruction.
When you use the disassembly view, the disassembly instructions
displayed in the source area are not guaranteed to be accurate because
it is not always possible to distinguish data from instructions. Because
of the possible inaccuracies, we recommend that you have a copy of
the listing that was created by the compiler or by HLASM. z/OS Debugger keeps
the disassembly view as accurate as possible by refreshing the Source
window whenever it processes the machine code, for example, after
a STEP command.