<s>
The	O
IBM	O
2780	B-Device
and	O
the	O
IBM	O
3780	B-Device
are	O
devices	O
developed	O
by	O
IBM	O
to	O
perform	O
remote	B-Protocol
job	I-Protocol
entry	I-Protocol
(	O
RJE	B-Protocol
)	O
and	O
other	O
batch	O
functions	O
over	O
telephone	O
lines	O
;	O
they	O
communicate	O
with	O
the	O
mainframe	B-Architecture
via	O
Binary	B-Protocol
Synchronous	I-Protocol
Communications	I-Protocol
(	O
BSC	O
or	O
Bisync	B-Protocol
)	O
and	O
replaced	O
older	O
terminals	O
using	O
synchronous	B-Protocol
transmit-receive	I-Protocol
(	O
STR	O
)	O
.	O
</s>
<s>
In	O
addition	O
,	O
IBM	O
has	O
developed	O
workstation	O
programs	O
for	O
the	O
1130	B-Device
,	O
360/20	B-Device
,	O
2922	B-Device
,	O
System/360	B-Application
other	I-Application
than	I-Application
360/20	I-Application
,	O
System/370	B-Device
and	O
System/3	B-Device
.	O
</s>
<s>
The	O
2780	B-Device
Data	O
Transmission	O
Terminal	O
first	O
shipped	O
in	O
1967	O
.	O
</s>
<s>
A	O
card	O
reader/punch	O
unit	O
,	O
similar	O
to	O
an	O
IBM	B-Device
1442	I-Device
,	O
that	O
can	O
read	O
up	O
to	O
400	O
cards	O
per	O
minute	O
(	O
cpm	O
)	O
and	O
can	O
punch	O
up	O
to	O
355cpm	O
.	O
</s>
<s>
A	O
binary	B-Protocol
synchronous	I-Protocol
adapter	O
which	O
controls	O
the	O
flow	O
of	O
data	O
over	O
the	O
communications	O
line	O
.	O
</s>
<s>
The	O
2780	B-Device
is	O
capable	O
of	O
local	O
(	O
offline	O
)	O
card	O
to	O
print	O
operation	O
.	O
</s>
<s>
Model	O
1	O
:	O
Can	O
read	O
punched	B-Architecture
cards	I-Architecture
and	O
transmit	O
the	O
data	O
to	O
a	O
remote	O
host	B-Device
computer	I-Device
,	O
and	O
can	O
receive	O
and	O
print	O
data	O
sent	O
by	O
the	O
host	O
.	O
</s>
<s>
Model	O
2	O
:	O
Same	O
as	O
Model	O
1	O
but	O
adds	O
the	O
ability	O
to	O
punch	B-Architecture
card	I-Architecture
data	O
received	O
from	O
the	O
host	O
.	O
</s>
<s>
Model	O
4	O
:	O
Can	O
read	O
and	O
punch	B-Architecture
card	I-Architecture
data	O
,	O
but	O
has	O
no	O
printing	O
capabilities	O
.	O
</s>
<s>
The	O
2780	B-Device
uses	O
a	O
dedicated	O
communication	O
line	O
at	O
speeds	O
of	O
1200	O
,	O
2000	O
,	O
2400	O
or	O
4800	O
bits	O
per	O
second	O
.	O
</s>
<s>
It	O
can	O
communicate	O
in	O
Transcode	B-Device
(	O
a	O
6-bit	O
code	O
)	O
,	O
8-bit	O
EBCDIC	B-Language
,	O
or	O
7-bit	B-Protocol
ASCII	I-Protocol
.	O
</s>
<s>
In	O
May	O
1972	O
,	O
IBM	O
announced	O
the	O
IBM	O
3780	B-Device
,	O
an	O
enhanced	O
version	O
of	O
the	O
2780	B-Device
.	O
</s>
<s>
The	O
3780	B-Device
was	O
developed	O
by	O
IBM	O
's	O
Data	O
Processing	O
Division	O
(	O
DPD	O
)	O
.	O
</s>
<s>
The	O
3780	B-Device
drops	O
Transcode	B-Device
support	O
and	O
incorporates	O
several	O
performance	O
enhancements	O
.	O
</s>
<s>
It	O
supports	O
compression	O
of	O
blank	O
fields	O
in	O
data	O
using	O
run-length	B-Algorithm
encoding	I-Algorithm
.	O
</s>
<s>
It	O
provides	O
the	O
ability	O
to	O
interleave	O
data	O
between	O
devices	O
,	O
introduces	O
double	B-Algorithm
buffering	I-Algorithm
,	O
and	O
adds	O
support	O
for	O
the	O
Wait-before-transmit	O
ACKnowledgement	O
(	O
WACK	O
)	O
and	O
Temporary	O
Text	O
Delay	O
(	O
TTD	O
)	O
Binary	B-Protocol
Synchronous	I-Protocol
control	O
characters	O
.	O
</s>
<s>
The	O
integrated	O
punched	B-Architecture
card	I-Architecture
unit	O
can	O
read	O
cards	O
at	O
600	O
cards	O
per	O
minute	O
.	O
</s>
<s>
It	O
punches	O
160	O
columns	O
per	O
second	O
,	O
or	O
91	O
cards	O
per	O
minute	O
if	O
all	O
80	B-Architecture
columns	I-Architecture
are	O
punched	O
.	O
</s>
<s>
The	O
IBM	O
2780	B-Device
and	O
3780	B-Device
were	O
later	O
emulated	B-Application
on	O
various	O
types	O
of	O
equipment	O
,	O
including	O
eventually	O
the	O
personal	B-Device
computer	I-Device
.	O
</s>
<s>
In	O
1974	O
IBM	O
Data	O
Processing	O
Division	O
(	O
DPD	O
)	O
offered	O
a	O
successor	O
to	O
the	O
3780	B-Device
,	O
called	O
the	O
3770	O
Data	O
Communications	O
System	O
,	O
supporting	O
SDLC	O
,	O
BSC	O
,	O
BSC	O
Multi-leaving	O
and	O
SNA	B-Architecture
,	O
depending	O
on	O
the	O
configuration	O
.	O
</s>
<s>
Except	O
for	O
the	O
RJE	B-Protocol
workstation	O
programs	O
in	O
OS/360	B-Application
,	O
these	O
programs	O
use	O
a	O
variation	O
of	O
BSC	O
known	O
as	O
Multi-leaving	O
.	O
</s>
<s>
Systems	B-Architecture
Network	I-Architecture
Architecture	I-Architecture
(	O
SNA	B-Architecture
)	O
and	O
TCP/IP	B-Protocol
.	O
</s>
