Ibm 2740 Communication Terminal, Model 1; Special Features, Model - IBM 2740-1 System Reference Manual

The IBM 2740 Communication Terminal, Model 1
provides the capabilities of the standard Selectric
typewriter combined with the added convenience and
flexibility of a communications terminal.
this dual-purpose unit can alternately function as:
• a document writer for correspondence or other
normal secretarial applications (local mode);
• a data sending and receiving unit over com­
munication lines (communicate mode), to an­
other 2740 terminal (or terminals) or to a
computer using an IBM 2701 Data Adapter Unit,
an IBM 2702 or 2703 Transmission Control Unit,
or an IBM 2712 Remote Multiplexer connected to
a 2702 or 2703. Hereafter the above units will
be referred to as multiplexers for ease of
reading.
This Tele-processing terminal presents an op­
portunity for any company to provide quality co rre s­
pondence copy at a customer's location to complete
an inquiry-reply cycle on a same-day basis.
means that the 2740 can accomplish a significant
time reduction in the normal cycle time involved in
obtaining vendor information for executive-level
decision making. With this terminal the total cycle
time from the customer-initiated inquiry to receipt
of the vendor reply is reduced from days (or weeks)
to hours (or minutes).
The IBM 2740 Communication Terminal Model 1
(Figure 1) is a typing terminal that can be operated
by a typist with a minimum of additional training.
The major advantages of the basic Selectric
typewriter are retained, and added to these is the
additional flexibility provided by the ability to com­
municate between remote locations.
offers the exclusive Selectric features of:
Stroke Storage. This permits faster keying action
due to the reduction of interlocking action between
the keys. Thus, when two keys are struck in rapid
succession, the second character is stored until
the first is printed.
*Perforated Tape and Transmission Code for Binary Coded
Decimal environments, and Perforated Tape and Trans­
mission Code for Extended Binary Coded Decimal environ­
ments (see code charts in Appendix. )

IBM 2740 COMMUNICATION TERMINAL, MODEL 1

Typamatic Index Key. Pressing and releasing this
key moves the paper up one line space. Pressing
and holding this key down brings about the typamatic
action, which causes the paper to rapidly line space
Thus,
until the key is released.
Interchangeable Print Elem ents. The print elements
available for the 2740 Model 1 (PTTC/BCD* *, and
PTTC/EBCD* and Correspondence) are easily inter­
changed.
the spring levers or raising the handle (depending
upon the element being used) and lifting it off the unit.
The other element is positioned by snapping it into
place.
NOTE: A choice of print elements (PTTC/BCD, PTTC/EBCD,
Although the PTTC/BCD and PTTC/EBCD print
elements are primarily used for term inal-to-
computer applications (such as on-line computation
or programming) they can also be used for term inal-
This
to-term inal applications (such as inter/intra company
communication or executive correspondence). How­
ever, the standard Selectric typewriter print element
can also be used for terminal-to-computer appli­
cations (such as text handling) provided the users
program is designed to accept the unique line code
assignments for the associated graphics.
NOTE: The Correspondence code and the PTTC/BCD code (with
The graphics and associated line transm ission bit
values for the Correspondence code differ from the
bit values of the PTTC/BCD and PTTC/EBCD codes.
This typewriter
(See code charts and keyboards in Appendix). Al­
though a choice of print elements is available, it is
important that all interconnected terminals use the
same type of print element: either all standard
Selectric typewriter, all PTTC/BCD, or all PTTC/
EBCD. Although the PTTC/BCD print element is
manually interchangeable with the PTTC/EBCD
print element (same line bit value assignments), the
standard Selectric typewriter print element is not
interchangeable with either of these print elements.
In all cases, the keyboard interposers must match
the associated print element to be used.
This is accomplished by either pressing
or standard Selectric typewriter) is available at the tim e the
2740 Model 1 term inal is ordered.
their associated keyboard arrangements and print elements)
are not S ystem /360 Type 1 Program supported.
IBM 2740 Communication Terminal, Model 1 1