<s>
The	O
Hazeltine	B-Device
2000	I-Device
is	O
one	O
of	O
the	O
first	O
general-purpose	O
"	O
smart	O
"	O
computer	B-General_Concept
terminals	I-General_Concept
,	O
introduced	O
in	O
October	O
1970	O
at	O
a	O
price	O
of	O
$	O
2,995	O
(	O
)	O
.	O
</s>
<s>
While	O
earlier	O
terminal	O
systems	O
included	O
"	O
smart	O
"	O
editing	O
features	O
,	O
notably	O
the	O
IBM	B-Device
2260	I-Device
,	O
the	O
Hazeltine	B-Device
2000	I-Device
was	O
the	O
first	O
that	O
used	O
a	O
standard	O
RS-232	O
interface	O
and	O
sent	O
its	O
control	O
sequences	O
in	O
the	O
data	O
stream	O
.	O
</s>
<s>
It	O
could	O
be	O
attached	O
to	O
any	O
contemporary	O
minicomputer	B-Architecture
or	O
mainframe	B-Architecture
that	O
had	O
a	O
serial	B-Protocol
port	I-Protocol
and	O
used	O
ASCII-standard	O
character	B-General_Concept
sets	I-General_Concept
.	O
</s>
<s>
One	O
advanced	O
feature	O
of	O
the	O
design	O
was	O
the	O
concept	O
of	O
"	O
batch	B-General_Concept
mode	I-General_Concept
"	O
that	O
cached	O
data	O
being	O
typed	O
by	O
the	O
user	O
and	O
sent	O
it	O
all	O
at	O
once	O
to	O
the	O
host	O
.	O
</s>
<s>
The	O
Hazeltine	B-Device
1500	I-Device
was	O
a	O
lower-cost	O
version	O
introduced	O
in	O
1977	O
.	O
</s>
<s>
In	O
contrast	O
to	O
most	O
glass	O
terminals	O
of	O
the	O
era	O
,	O
the	O
2000	O
offered	O
only	O
RS-232	O
,	O
lacking	O
the	O
common	O
current	O
loop	O
based	O
on	O
the	O
Teletype	B-Application
Model	I-Application
33	I-Application
that	O
was	O
widely	O
used	O
as	O
an	O
ad	O
hoc	O
terminal	O
in	O
the	O
1970s	O
.	O
</s>
<s>
A	O
second	O
switch	O
,	O
"	O
CA	O
"	O
,	O
added	O
additional	O
characters	O
to	O
sent	O
data	O
in	O
order	O
to	O
turn	O
around	O
the	O
communications	O
channel	O
in	O
half-duplex	O
modems	B-Application
like	O
the	O
WE202C	O
.	O
</s>
<s>
This	O
also	O
had	O
the	O
side-effect	O
of	O
reducing	O
the	O
speeds	O
;	O
when	O
turned	O
on	O
the	O
highest	O
speed	O
was	O
1200bit/s	O
,	O
but	O
it	O
also	O
supported	O
a	O
wider	O
variety	O
of	O
speeds	O
below	O
that	O
to	O
match	O
the	O
variety	O
of	O
speeds	O
seen	O
with	O
these	O
modems	B-Application
,	O
adding	O
150	O
and	O
600bit/s	O
.	O
</s>
<s>
The	O
system	O
also	O
had	O
outputs	O
for	O
a	O
printer	O
,	O
cassette	B-Device
storage	O
,	O
and	O
the	O
video	O
signal	O
so	O
it	O
could	O
be	O
mirrored	O
on	O
up	O
to	O
three	O
additional	O
screens	O
.	O
</s>
<s>
The	O
keyboard	B-Device
could	O
be	O
detached	O
,	O
connecting	O
to	O
the	O
terminal	O
using	O
a	O
54-pin	O
HDR	O
connector	O
.	O
</s>
<s>
It	O
had	O
a	O
51-key	O
typewriter	O
layout	O
main	O
section	O
,	O
along	O
with	O
a	O
numeric	B-Device
keypad	I-Device
to	O
the	O
right	O
,	O
and	O
a	O
cursor	B-Device
control	I-Device
section	I-Device
to	O
the	O
right	O
of	O
the	O
numeric	B-Device
keypad	I-Device
.	O
</s>
<s>
Parity	B-Error_Name
was	O
selected	O
using	O
a	O
rear-panel	O
rotating	O
switch	O
,	O
odd	O
,	O
even	O
,	O
always-1	O
or	O
always-0	O
.	O
</s>
<s>
A	O
parity	B-Error_Name
error	I-Error_Name
would	O
cause	O
the	O
parity	B-Error_Name
lamp	O
to	O
light	O
,	O
which	O
could	O
be	O
cleared	O
by	O
pressing	O
it	O
.	O
</s>
<s>
The	O
base-model	O
system	O
had	O
a	O
character	B-General_Concept
set	I-General_Concept
of	O
64	O
characters	O
covering	O
the	O
upper	O
case	O
ASCII	B-Protocol
set	O
.	O
</s>
<s>
A	O
key	O
feature	O
of	O
the	O
2000	O
was	O
its	O
ability	O
to	O
be	O
put	O
into	O
"	O
batch	B-General_Concept
mode	I-General_Concept
"	O
,	O
either	O
by	O
pressing	O
the	O
appropriate	O
lamp/button	O
on	O
the	O
right	O
of	O
the	O
keyboard	B-Device
,	O
or	O
by	O
sending	O
the	O
appropriate	O
command	O
as	O
ASCII	B-Protocol
codes	I-Protocol
from	O
the	O
host	O
computer	O
.	O
</s>
<s>
In	O
batch	B-General_Concept
mode	I-General_Concept
,	O
typing	O
on	O
the	O
keyboard	B-Device
was	O
not	O
immediately	O
sent	O
to	O
the	O
host	O
,	O
but	O
was	O
instead	O
buffered	O
into	O
the	O
2KB	O
of	O
internal	O
core	B-General_Concept
memory	I-General_Concept
.	O
</s>
<s>
Batch	B-General_Concept
mode	I-General_Concept
was	O
normally	O
used	O
in	O
conjunction	O
with	O
a	O
separate	O
feature	O
,	O
foreground/background	O
mode	O
.	O
</s>
<s>
The	O
key	O
feature	O
of	O
this	O
concept	O
is	O
that	O
common	O
commands	O
,	O
like	O
clear	O
screen	O
,	O
could	O
be	O
issued	O
to	O
clear	O
only	O
the	O
foreground	O
or	O
background	O
data	O
,	O
and	O
batch	B-General_Concept
mode	I-General_Concept
only	O
sends	O
the	O
foreground	O
characters	O
.	O
</s>
<s>
Additionally	O
,	O
the	O
cursor	B-Device
keys	I-Device
and	O
tab	O
key	O
skipped	O
over	O
background	O
characters	O
,	O
allowing	O
the	O
user	O
to	O
easily	O
move	O
around	O
the	O
form	O
from	O
field	O
to	O
field	O
.	O
</s>
<s>
These	O
included	O
(	O
shift	O
out	O
)	O
to	O
trigger	O
a	O
transmit	O
in	O
batch	B-General_Concept
mode	I-General_Concept
,	O
(	O
unit	O
separator	O
)	O
to	O
indicate	O
following	O
data	O
was	O
in	O
foreground	O
mode	O
,	O
(	O
end	O
of	O
medium	O
)	O
to	O
indicate	O
background	O
,	O
(	O
file	O
separator	O
)	O
to	O
clear	O
the	O
screen	O
,	O
or	O
(	O
group	O
separator	O
)	O
to	O
clear	O
just	O
the	O
foreground	O
.	O
</s>
<s>
allowed	O
the	O
cursor	O
to	O
be	O
sent	O
to	O
an	O
indicated	O
location	O
on	O
the	O
screen	O
by	O
following	O
it	O
with	O
two	O
ASCII	B-Protocol
characters	I-Protocol
where	O
the	O
character	B-General_Concept
code	I-General_Concept
indicated	O
a	O
number	O
.	O
</s>
<s>
For	O
instance	O
,	O
the	O
,	O
ASCII	B-Protocol
code	I-Protocol
0	O
,	O
would	O
send	O
the	O
cursor	O
to	O
row	O
or	O
column	O
0	O
.	O
</s>
