IBM System/370 145 Reference Summary page 145

Byte Bit
0
1
2
0 3
4
5
6
7
0
1
2
1 3
4
5
6
7
0
1
2
2 3
4
5
6
7
0
1
2
3
3
4
5
6
6
G1TAG (SX1 Only) 23,2B,33,3B
Fwd= B3
GB3
I>
GC641
Bkwd =BO
\
Spare
GDRL6
f
GC414
GDRL 7
GBD GB P
l
GL
GR
GBO
GB1 GC411
GB2
GB3
Count Ready GB413
Count Zero GB414
GR Full GB311
Interrupt Cond GB413
Share Error GB412
Spare
~
Position Code GB711
'
Communication
f
GB611
with Data Flow
(Data, Command,
I
Address, Status) '
_!._
Selector Channel Logics
GA Pages Common to All Channels
GB and GC =Channel 1
GF and GG =Channel 2
GK and GL =Channel 3
GP and GQ = Channel 4
11.21
Ill