IBM 3741 Data Station Reference Manual page 105

The choice of format control method depends on the user's
requirements. Local format control would probably be
selected if:
• Control and flexibility of print formatting is desired at
local site.
• Processing unit output reprogramming can be avoided.
Processing unit format control would probably be selected if:
• Maximum teleprocessing efficiency is important
(accomplished by eliminating unprinted blanks, zeros,
etc. and by packing data into large transmission blocks).
• Maximum data storage on disk(s) is desired.
• Central control of printer formatting is desired.
Local Format Control
Under local format control, printer format instructions
reside in program buffers. The operator loads the printer
format programs into the program buffers the same as key
entry programs are loaded. See
Printer Instruction Set
for information on writing printer format programs. Up
to nine printer format programs can be written and loaded
at one time. The printer format programs can be loaded
into program buffers 1 through 9.
01 '--
_---'I
o
o
JI
Record is read into
current record buffer.
Program buffer A contains the horizontal tab stop, vertical
skip stop, and printer format program selection characters.
See
Printer Format Program Select, HorizontalTab/Vertical
Skip Forms Control
for a complete description .
Figure 51 shows the data flow for local format control.
Printer Instruction Set
The printer instruction set is a group of printer format
control characters that provide information for printing
records. A printer format program consists of printer
format control records and indicates the printing format
for a record. Printer format programs can be loaded into
program buffers 1 through 9. A printer format program
can be selected automatically or manually by the operator.
For information on printer format selection, see Figure 53.
Figure 52 lists each printer format control character and its
meaning. The control characters are for the 3713, the
3715, and the 3717 unless otherwise indicated.
Program Buffer A
The control unit formats the
print line buffer using appro-
priate program buffer, program
buffer A, and data record.
Print Line Buffer
1
Program Buffers
1 through 9
Figure 51. Data Flow for Local Format Control
Printout
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IBM 3713, IBM 3715, and IBM 3717 Printers 99