Maximum number of features per 2703 is four. This
feature cannot be installed if any mM Line Set lA or
1B features are installed.
Telegraph Line Set This feature provides the line terminations for eight
half-duplex telegraph lines. A maximum of twelve
of these features are permitted on anyone 2703. Telegraph Line Set Expander
This feature provides for eight additional half-duplex
line terminations as an expansion of the Telegraph
Line Set feature. Each expander feature is associatec
with the basic Telegraph Line Set feature on a one to
one basis, up to a maximum of ten per 2703. World Trade Telegraph Single-Current Line Set This feature provides the line termination for eight
simplex or half-duplex single-current telegraph lines
operating at 50 or 75 bps. Two simplex connections
can be used as one full-duplex connection for a maxi­
mum of four full-duplex lines per line set. The
maximum number of line sets is six per start-stop
Base and 12 per 2703. World Trade Telegraph Single-Current Line Set Expander
This feature provides an additional eight simplex or
half-duplex single-current telegraph lines per line se
The maximum number of line set expanders are: One per line set.
Five per Start-Stop Base.
Ten per 2703. World Trade Telegraph Double-Current Line Set This feature provides the attachment of up to eight
simplex or half-duplex double-current telegraph lines
operating at 50, 75, or 100 bps via the IBM 3945
Model 11 Telegraph Line Termination (serial #200 or
above). Two simplex connections can be used as one
full-duplex connection for a maximum of four full­
duplex lines per line set. The maximum number of
this feature is six per Start-Stop Base and 12 per 2703. The 2703 provides power for a limited number of IBM
3945 Model 11 'So When the number of 3945's exceed
this limit, the IBM 3945 Additional Power Supply Feature #2822 must be installed to power the extra
units. The maximum number of 3945 Model 11 's that
can be powered by each 2703 Start-Stop Base is
dependent of the mixture of single-current and double­
current line sets. The number of 3945's that can be
powered by each base is:
No. of Single- No. of 2703 Current Line Sets powered 3945's
1 4
2-5 3
6 or more 2
World Trade Telegraph Double-Current Line Set Expander
This feature provides an additional eight simplex or
half-duplex double-current telegraph lines per line
set. The maximum number of line set expanders are: One per line set.
Fi ve per Start-Stop Base.
Ten per 2703. Line-Speed Options
These speed options provide nine spe,cific operating
speeds from 45.5 bps to 600 bps to accommodate the
wide range of start/stop type terminals attachable
to the IBM 2703. Anyone line-speed option of a given
36.1

Line Sase Positions Maximum*
Number
A S (
of Lines SiS I SiS I ! SiS I
sis I sis I --- SIS I siS I SiS II SiS I siS I Sync IA
176 SiS I sis I Sync IS Sis I SIS I Sync IIA SiS I SiS II Sis II
sis I Sync I A Sync IA 136 Sis I siS II Sync IA Sis I SiS II Sync IS ;28 SiS I Sync IS Sync IA
siS I Sync IA Sync IIA 124 SIS I Sync IS Sync IS 120 siS I Sync IS Sync IIA 116
sis I SIS II ---
sis I --- Sync IA 112
Sis I Sync II A Sync IIA
sis I --- Sync IS 104 sis I --- Sync IIA 100 sis I ------88
sis II SIS II siS II
sis II siS II Sync IA 72
sis II Sync I A Sync IA
sis II sis II Sync IS 64 siS II Sync IS Sync IA SiS II SiS II Sync rrA
sis II Sync IA Sync IIA 60 SIS II Sync IS Sync IS 56 SIS II Sync IS Sync IIA 52
siS II SIS II ---
--- Sync I A Sync IA siS II --- Sync IA
48
siS II Sync IIA Sync nA SiS II --- Sync IS 40 --- Sync IS Sync IA
Sis II --- Sync IrA
--- Sync IA Sync IIA
36
--- Sync IS Sync IS 32
--- --- Sync IA SIS II ------24
--- Sync II A Sync IIA
--- --- Sync IS 16
--- --- Sync IIA 12
Figure 8. Line Base Configurations
LEGEND SISI - Start-Stop Sase Type I (88 Max lines) siS II -Start-Stop Sase Type II (24 Max lines) Sync I A -Synchronous Base Type I A (24 Max lines) Sync I B -Synchronous Sase Type [B (16 Max lines)
Sync IIA -Synchronous Base Type IIA (12 Max lines)
Notes: I. The maximum total Start-Stop type bases is three,
while for the synchronous bases it is two. However,
the combined maximum total is three.
2. The line base types shown in this chart are assigned
by the base position (A, B or () to conform with ordering
procedures as follows:
A-F irst SiS bose.
B-Second SiS base, or Second Sync base.
(-Third sis base, or First Sync base.
* This maximum may be decreased when a 2712 Attachment or
the Sync (lock feature is attached to the 2703. Th is decrease
occurs whenever any 2712 Expander feature is installed, and
is as follows:
---Modell Expander -each of these features decreases the
maximum available I ines by six (6).
---Model 2 Expander -each of these features decreases the
maximum available lines by two (2).
37