IBM System/370 145 Reference Summary page 134

(RM811, KF031, MT215, MT332)
Byte Bit ACBOA
0
1
2
Spares
0 3
ACBO
4
5
Compared with M1 Bits 4-7 on all
6
Main Storage Accesses
7
0
Compared with M2 Bits 0-4 for all
1 Storage Accesses (Bits 0 and 1 May
2
Be Altered for Control Storage
1 3 Accesses)
4
ACB1
5
5
=
0 Internal Storage Only
6
67
=
00
=
16K Bound
7
01
=
32K Bound
10
=
48K Bound
11
=
64K Bound
5
=
1 Ext Storage
67
=
00
=
128K Ext Storage
01
=
256K Ext Storage
2
0-7 Spare
3
0-7
Spare
(MC015-016)
11.10