IBM 3741 Data Station Reference Manual page 129

HOW FORMAT CONTROL WORKS
Figures 71 and 72 show the data flow, when using format
control, for reading or punching cards with the data re-
corder attachment feature.
(Input)
o
1-
1 _ _ ...... 1,
(Input Buffer)
Record is
read into
current record
buffer
Program
Level A
Program
Level 1-8
(Output Buffer)
The record moves to
program level 9, where
it is formatted using
program level A and
the appropriate
program level.
Data
Recorder
Storage Area
(Output)
Punched Card
/
(Input)
Read Card
Data
Recorder
Storage Area
Program
Level A
Program
Level 1-8
(Input Buffer)
The record moves to
program level 9, where
it is formatted using
t----~
program level A and
the appropriate
program level.
(Output Buffer)
Current
Record
Buffer
(Output)
0' .... __ .......
1,
•
o
I
Figure 71. Data Flow When Punching Cards with Format Control Figure 72. Data Flow When Reading Cards with Format Control
Data Recorder Attachment Feature 123