IBM System/370 145 Reference Summary page 146

Byte Bit FBAK - 20 (IFA Only)
0 0-7 FWB Spare
0
32K-
1
16K -
2 SK-
1 3
FCH
4K- ··
File
4
2K - Counter
5
1048 High
6
512
7 256
(JK211
I
0
128
1
64
2 32
2 3
FCL 16
File
4
8
Counter
5
4 Low
6
2
7
1
(JK311
I
0
*Op Code (Read)
1
*Op Code (Write)
2
Address Mark (Omit)
3
3
FOP Search
4
Scan
5
Index Hold
6
Format
7
Skip
(JK411-412)
•
11.22