IBM System/370 145 Reference Summary page 132

Byte Bit MCKA07
0
LS A Source Address Check
1
LS B Source Address Check
2 LS A Destination Address Check
0 3
LS B Destination Address Check
4 Destination Byte Control Check
5
LS A, B Destination Address Compare
6 LS Control Assembler Check
7
C-Register Parity Check
RE021
RE022
0
ACB Register Parity Check
1
LS Compare Check
2
Flush Through Check
1 3
H-Register Parity Check
4 Spare
5
P-Register Parity Check
6 T-Register Parity Check
7
L-Register Parity Check
RE023
RE024
0
ALU 2 Halfsum Check
1
ALU 3 Halfsum Check
2
ALU Logical Check
2
3
B-Register Shift Check
4
A-Register Parity Check
5
B-Register Parity Check
6
Z-Register Parity Check
7
D-Register Parity Check
RE031
RE032
RE033
0
External Destination X-Compare
1
External Destination Y-Compare
2
External Source Y-Check
3 3
External Control Assembler Parity Check
4
Interval Timer Parity Check
5
S-Register Duplicate (Compare) Check
6
Time-of-Day Clock Parity Check
7
Control Storage Address Check
RE041
RE034
11.8