IBM 3741 Data Station Reference Manual page 102

IBM 3715 PRINTER
The IBM 3715 Printer is available as a feature attachment on
the 3741. It enables the 3741 to prepare hard copy from
disk. The 3715 is available in two models. The Model 1 prints
at a maximum rate of 40 characters per second and the Model
2 prints at a maximum rate of 80 characters per second.
The 3715 has these characteristics:
• Bi-directional printing (left to right and then right to
left). The 3715 bi-directional printing operates as follows.
The print head moves from the left margin. After the
line is printed, the print head continues far enough to the
right to enable the printing of the next line from right to
left. The next line is then printed and the print head re-
turns to the left margin again.
• Programmable editing capability.
• Automatic continuation of printing from disk 1 to disk
2 when a data set on disk 1 is continued on disk 2 (if the
3741 has the second disk feature).
• Allows unattended print operations under the control
of the expanded communications feature (Chapter 10,
Communications) .
• A maximum print line of 132 characters.
Note: If 132 characters are formatted for forms less than
132 characters wide, loss of data will occur as the print
head leaves the form.
• Capability of using individual or continuous forms. Maxi-
mum number of copies is six, but for optimum feeding
and stacking IBM recommends a maximum of four parts
per form.
• Adjustable forms tractor that allows the use of various
width forms. The forms can be from 3 to 14.5 inches
(76.2 to 368.3 mm) wide for individual forms and from
3 to 15 inches (76.2 to 381.0 mm) wide for continuous
forms.
• A maximum print rate of 40 characters per second on the
Model 1 and a maximum print rate of 80 characters per
second on the Model 2.
• Print position spacing of 10 characters per inch
(25.4 mm).
• Printing with or without format control.
• Use of both 3713 and 3717 printer programs.
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• Spaces are inserted for characters not represented on the
3741 keyboard. If the 3741 PROG NUM SH I FT switch
is in the ALL CHAR position, no error is indicated. If
the switch is in the NUMBERS ONL Y position, the
printer stops and an error is indicated on the CRT dis-
play. The operator can press RESET or R EC ADV to
continue printing, or RESET twice to discontinue the
printer mode.
• Printing of constant data stored in program buffers.
• Program chaining.
• Page numbering and page heading capability.
• Stapled forms or continuous card stock cannot be used.
The following formula shows how to determine nominal
throughput for most 3715 Printer applications.
L
L
PT
RL
lines per minute
60
(PT x R L)
+
(LF x N L)
+
0.15
Character print time
0.025 for 3715 Model 1
0.0125 for 3715 Model 2
Character length of print line
LF
Line feed time (0.030 seconds per line)
NL
Number of line feeds per print line
For example, nominal speed for a 3715 Model 2 printing
40-character print lines and double spacing is determined
as follows:
L
=
60
=
84.5 lines per
(0.0125 x 40)
+
(0.030 x 2)
+
0.15 minute
In some applications, throughput may be reduced by:
• Multiple disk reads per print line
• Complex editing and reformatting
• Print line length of less than 10 characters .
IBM 3715 Forms Stand Feature
This feature permits stacking of continuous forms on a stand
above floor level.