<s>
The	O
HP	O
2640A	O
and	O
other	O
HP	O
264X	O
models	O
were	O
block-mode	O
"	O
smart	O
"	O
and	O
intelligent	O
ASCII	B-Protocol
standard	O
serial	B-General_Concept
terminals	I-General_Concept
produced	O
by	O
Hewlett-Packard	O
using	O
the	O
Intel	B-General_Concept
8008	I-General_Concept
and	O
8080	B-General_Concept
microprocessors	I-General_Concept
.	O
</s>
<s>
Based	O
on	O
the	O
Intel	B-General_Concept
8008	I-General_Concept
CPU	O
,	O
it	O
had	O
8	O
KB	O
of	O
ROM	O
firmware	O
and	O
came	O
standard	O
with	O
1	O
KB	O
of	O
RAM	O
,	O
expandable	O
up	O
to	O
8	O
KB	O
(	O
two	O
4	O
KB	O
semiconductor	O
RAM	O
cards	O
)	O
.	O
</s>
<s>
All	O
of	O
these	O
early	O
members	O
of	O
the	O
2640	O
series	O
had	O
the	O
relatively	O
slow	O
8008	B-General_Concept
CPU	O
running	O
at	O
700	O
kHz	O
,	O
and	O
they	O
were	O
thus	O
limited	O
to	O
speeds	O
of	O
2400	O
baud	O
.	O
</s>
<s>
The	O
2645A	O
was	O
the	O
first	O
terminal	O
in	O
the	O
2640	O
series	O
to	O
use	O
the	O
Intel	B-General_Concept
8080A	I-General_Concept
,	O
rather	O
than	O
the	O
8008	B-General_Concept
,	O
as	O
its	O
CPU	O
.	O
</s>
<s>
Almost	O
all	O
subsequent	O
2640-family	O
terminals	B-General_Concept
would	O
have	O
8080A	B-General_Concept
CPUs	O
,	O
all	O
running	O
at	O
2.5	O
MHz	O
.	O
</s>
<s>
The	O
2645A	O
was	O
followed	O
in	O
November	O
1976	O
by	O
the	O
2641A	O
,	O
a	O
2645A	O
derivative	O
designed	O
for	O
the	O
APL	B-Language
programming	I-Language
language	I-Language
,	O
and	O
in	O
April	O
1977	O
by	O
the	O
2645R	O
,	O
a	O
2645	O
which	O
supported	O
right-to-left	O
Arabic	O
text	O
as	O
well	O
as	O
left-to-right	O
text	O
in	O
Roman	O
letters	O
.	O
</s>
<s>
In	O
October	O
1980	O
,	O
HP	O
introduced	O
the	O
2642A	O
,	O
which	O
was	O
like	O
the	O
2645A	O
,	O
but	O
instead	O
of	O
optional	O
tape	O
cartridges	O
it	O
had	O
a	O
standard	O
5.25-inch	O
floppy	B-Device
disk	I-Device
drive	I-Device
storing	O
270	O
KB	O
per	O
diskette	B-Device
.	O
</s>
<s>
The	O
ultimate	O
and	O
final	O
model	O
in	O
the	O
2640	O
series	O
was	O
the	O
2647F	O
programmable	O
graphics	O
terminal	O
introduced	O
in	O
June	O
1982	O
,	O
an	O
improved	O
replacement	O
for	O
the	O
2647A	O
with	O
the	O
2642A	O
's	O
floppy	B-Device
drive	I-Device
.	O
</s>
<s>
Unlike	O
the	O
preceding	O
terminals	B-General_Concept
in	O
the	O
264X	O
family	O
that	O
had	O
8080A	B-General_Concept
CPUs	O
,	O
the	O
2647F	O
used	O
the	O
faster	O
Intel	B-General_Concept
8085A	I-General_Concept
running	O
at	O
4.9	O
MHz	O
.	O
</s>
<s>
and	O
infrequently	O
as	O
"	O
HP	B-General_Concept
2640	I-General_Concept
"	O
,	O
or	O
"	O
HP	O
2640A	O
"	O
(	O
both	O
with	O
a	O
blank	O
after	O
the	O
"	O
HP	O
"	O
)	O
,	O
or	O
"	O
2640	O
"	O
.	O
</s>
<s>
The	O
incorrect	O
"	O
HP2640	B-General_Concept
"	O
and	O
"	O
HP2640A	O
"	O
are	O
often	O
seen	O
outside	O
of	O
HP	O
.	O
</s>
<s>
The	O
functionality	O
defined	O
by	O
the	O
HP	O
264X	O
series	O
has	O
n't	O
changed	O
much	O
as	O
the	O
preferred	O
terminal	O
for	O
HP1000	B-Device
and	O
HP	B-Device
3000	I-Device
series	O
computers	O
.	O
</s>
<s>
They	O
never	O
achieved	O
the	O
fame	O
of	O
the	O
VT100	B-Device
among	O
programmers	O
,	O
but	O
included	O
sophisticated	O
features	O
not	O
found	O
in	O
the	O
VT100	B-Device
,	O
such	O
as	O
offline	O
forms	O
,	O
multipages	O
,	O
and	O
(	O
in	O
some	O
models	O
)	O
local	O
storage	O
.	O
</s>
<s>
The	O
keyboard	B-Device
had	O
flat	O
tops	O
,	O
similar	O
to	O
the	O
HP	B-Device
9800	I-Device
series	I-Device
desktop	I-Device
computers	I-Device
rather	O
than	O
the	O
curved	O
contours	O
now	O
considered	O
to	O
be	O
ergonomic	O
.	O
</s>
<s>
It	O
featured	O
three	O
keypad	O
areas	O
:	O
Alphabetic	O
,	O
numeric	O
,	O
and	O
an	O
array	O
of	O
cursor	O
positioning	O
and	O
editing	O
keys	O
somewhat	O
similar	O
to	O
modern	O
PC	B-Device
keyboard	I-Device
layouts	O
.	O
</s>
<s>
There	O
were	O
also	O
a	O
number	O
of	O
smaller	O
function	B-Application
and	O
feature	O
control	O
keys	O
arrayed	O
in	O
two	O
rows	O
above	O
the	O
normal	O
keypad	O
areas	O
.	O
</s>
<s>
The	O
keyboard	B-Device
chassis	O
was	O
separate	O
from	O
the	O
main	O
body	O
,	O
connected	O
via	O
a	O
thick	O
cable	O
.	O
</s>
<s>
The	O
keyboard	B-Device
used	O
a	O
bit-paired	B-Protocol
layout	O
(	O
similar	O
to	O
that	O
on	O
a	O
teleprinter	O
machine	O
)	O
rather	O
than	O
the	O
typewriter-paired	B-Protocol
arrangement	O
on	O
DEC	O
's	O
VT100	B-Device
.	O
</s>
<s>
Although	O
large	O
,	O
users	O
loved	O
the	O
keyboard	B-Device
because	O
"	O
it	O
had	O
a	O
key	O
for	O
everything	O
"	O
.	O
</s>
<s>
Paper	O
templates	O
were	O
available	O
for	O
some	O
application	O
programs	O
to	O
which	O
placed	O
legends	O
for	O
these	O
keys	O
on	O
the	O
keyboard	B-Device
.	O
</s>
<s>
Terminal	O
configuration	O
in	O
the	O
262X	O
series	O
was	O
done	O
entirely	O
through	O
the	O
screen-labeled	B-General_Concept
function	I-General_Concept
keys	I-General_Concept
rather	O
than	O
dedicated	O
keys	O
and	O
through	O
escape	O
sequences	O
sent	O
from	O
the	O
host	O
computer	O
.	O
</s>
<s>
The	O
on-screen	O
labeling	O
of	O
the	O
eight	O
function	B-Application
keys	I-Application
,	O
pioneered	O
by	O
the	O
HP	B-Device
300	I-Device
(	O
"	O
Amigo	O
"	O
)	O
computer	O
,	O
was	O
one	O
of	O
the	O
first	O
applications	O
of	O
a	O
hierarchical	O
menu	O
which	O
allows	O
accessing	O
many	O
functions	O
with	O
a	O
small	O
number	O
of	O
keys	O
.	O
</s>
<s>
The	O
microprocessor	B-Architecture
,	O
memory	O
,	O
serial	O
interface	O
card	O
,	O
and	O
various	O
optional	O
functions	O
were	O
each	O
on	O
separate	O
cards	O
.	O
</s>
<s>
The	O
manufacturing	O
area	O
was	O
across	O
from	O
R&D	O
cubicles	O
in	O
the	O
Data	B-General_Concept
Terminals	I-General_Concept
Division	O
in	O
Cupertino	O
.	O
</s>
<s>
The	O
testing	O
area	O
was	O
dubbed	O
"	O
beepland	O
"	O
because	O
it	O
had	O
racks	O
of	O
500	O
terminals	B-General_Concept
,	O
with	O
the	O
end	O
of	O
the	O
test	O
ending	O
in	O
a	O
beep	O
.	O
</s>
<s>
The	O
HP	B-General_Concept
2640	I-General_Concept
introduced	O
"	O
block	O
mode	O
"	O
,	O
similar	O
to	O
the	O
IBM	B-Operating_System
3270	I-Operating_System
(	O
although	O
the	O
IBM	B-Operating_System
3270	I-Operating_System
did	O
not	O
work	O
for	O
ASCII	B-Protocol
standard	O
serial	O
communications	O
)	O
.	O
</s>
<s>
The	O
fields	O
could	O
screen	O
for	O
alphabetic	O
or	O
numeric	O
characters	O
,	O
a	O
feature	O
beyond	O
Windows	B-Application
Forms	I-Application
today	O
.	O
</s>
<s>
It	O
also	O
supported	O
teletype	O
character	O
mode	O
like	O
a	O
standard	O
ASCII	B-Protocol
terminal	O
,	O
and	O
did	O
not	O
need	O
specialized	O
communications	O
like	O
IBM	O
.	O
</s>
<s>
The	O
hardware	O
was	O
radically	O
different	O
from	O
most	O
"	O
dumb	O
"	O
terminals	B-General_Concept
in	O
that	O
the	O
characters	O
were	O
not	O
stored	O
in	O
a	O
simple	O
data	O
array	O
.	O
</s>
<s>
This	O
data	O
structure	O
would	O
inspire	O
the	O
sparse	B-Algorithm
matrix	I-Algorithm
data	O
structure	O
for	O
the	O
Twin	O
spreadsheet	O
.	O
</s>
<s>
The	O
HP	B-General_Concept
2640	I-General_Concept
also	O
introduced	O
multiple	O
pages	O
of	O
memory	O
,	O
much	O
like	O
the	O
DOS	B-Device
box	O
in	O
Microsoft	B-Application
Windows	I-Application
today	O
,	O
and	O
the	O
page	O
up	O
and	O
page	O
down	O
key	O
which	O
appears	O
on	O
PC	B-Device
keyboards	I-Device
.	O
</s>
<s>
This	O
was	O
possible	O
in	O
many	O
terminals	B-General_Concept
of	O
the	O
day	O
,	O
but	O
the	O
HP	B-General_Concept
2640	I-General_Concept
was	O
smart	O
enough	O
to	O
only	O
retransmit	O
the	O
line	O
from	O
the	O
first	O
character	O
typed	O
by	O
the	O
user	O
,	O
omitting	O
,	O
for	O
example	O
,	O
the	O
operating	O
system	O
's	O
command	O
prompt	O
.	O
</s>
<s>
immediate	O
interrupt	O
of	O
the	O
host	O
)	O
such	O
as	O
control	O
y	O
and	O
function	B-Application
keys	I-Application
.	O
</s>
<s>
HP	O
Printer	O
Control	O
Language	O
shares	O
a	O
common	O
non-ANSI	O
escape	O
sequence	O
grammar	O
and	O
common	O
sequences	O
with	O
HP	O
terminals	B-General_Concept
.	O
</s>
<s>
In-house	O
developers	O
ported	O
TinyBASIC	O
to	O
the	O
HP	B-General_Concept
2645A	I-General_Concept
,	O
as	O
well	O
as	O
developing	O
several	O
games	O
in	O
assembler	O
(	O
most	O
notably	O
"	O
Keep	O
On	O
Drivin	O
 '	O
"	O
,	O
Tennis	O
and	O
Reversi	O
)	O
.	O
</s>
<s>
Another	O
later	O
model	O
used	O
floppy	B-Device
disks	I-Device
,	O
and	O
supported	O
drawing	O
forms	O
etch-a-sketch	O
style	O
and	O
would	O
compute	O
intersections	O
.	O
</s>
<s>
Also	O
notable	O
was	O
the	O
use	O
of	O
paper	O
labeled	O
function	B-Application
keys	I-Application
on	O
the	O
upper	O
left	O
.	O
</s>
<s>
These	O
were	O
built	O
into	O
the	O
next	O
generation	O
of	O
terminals	B-General_Concept
.	O
</s>
<s>
The	O
HP	B-General_Concept
2647	I-General_Concept
had	O
a	O
variant	O
of	O
Microsoft	B-Language
BASIC	I-Language
with	O
AGL	B-Language
(	O
HP	O
's	O
standard	O
for	O
plotting	O
)	O
built	O
in	O
,	O
and	O
perhaps	O
the	O
first	O
real	O
business	O
charting	O
for	O
a	O
microcomputer	O
,	O
complete	O
with	O
3D	O
cross-hatched	O
pie	B-Application
charts	I-Application
.	O
</s>
<s>
Multiplot	O
was	O
the	O
model	O
for	O
the	O
PC	O
based	O
Chartman	O
by	O
the	O
Cambridge	O
company	O
that	O
also	O
produced	O
the	O
Twin	O
spreadsheet	O
1-2-3	O
clone	O
which	O
introduced	O
HP	B-General_Concept
2640	I-General_Concept
style	O
forms	O
to	O
PC	O
applications	O
.	O
</s>
<s>
The	O
Dual	O
Z80	B-General_Concept
CP/M	B-Application
used	O
the	O
form	O
factor	O
and	O
terminal	B-Application
emulation	I-Application
of	O
the	O
HP	O
2621	O
terminal	O
.	O
</s>
<s>
The	O
HP-150	B-Device
had	O
the	O
terminal	O
capabilities	O
of	O
the	O
HP	O
2623	O
graphics	O
terminal	O
in	O
a	O
smaller	O
package	O
(	O
9	O
"	O
screen	O
)	O
.	O
</s>
<s>
The	O
great	O
over-reach	O
was	O
a	O
color	O
graphics	O
terminal	O
that	O
cost	O
more	O
than	O
the	O
HP	B-General_Concept
2647	I-General_Concept
monochrome	O
graphics	O
workstation	O
that	O
sold	O
very	O
few	O
units	O
but	O
cost	O
a	O
huge	O
effort	O
to	O
develop	O
.	O
</s>
<s>
Eventually	O
,	O
HP	O
ended	O
up	O
selling	O
essentially	O
a	O
low-cost	O
version	O
of	O
the	O
HP	B-General_Concept
2640	I-General_Concept
.	O
</s>
<s>
Today	O
,	O
terminal	B-Application
emulators	I-Application
still	O
implement	O
the	O
late	O
1970s	O
feature	O
set	O
of	O
these	O
terminals	B-General_Concept
on	O
common	O
PCs	O
.	O
</s>
