<s>
Videotex	B-Operating_System
(	O
or	O
interactive	O
videotex	B-Operating_System
)	O
was	O
one	O
of	O
the	O
earliest	O
implementations	O
of	O
an	O
end-user	O
information	O
system	O
.	O
</s>
<s>
From	O
the	O
late	O
1970s	O
to	O
early	O
2010s	O
,	O
it	O
was	O
used	O
to	O
deliver	O
information	O
(	O
usually	O
pages	O
of	O
text	O
)	O
to	O
a	O
user	O
in	O
computer-like	O
format	O
,	O
typically	O
to	O
be	O
displayed	O
on	O
a	O
television	O
or	O
a	O
dumb	O
terminal	B-General_Concept
.	O
</s>
<s>
In	O
a	O
strict	O
definition	O
,	O
videotex	B-Operating_System
is	O
any	O
system	O
that	O
provides	O
interactive	O
content	O
and	O
displays	O
it	O
on	O
a	O
video	O
monitor	O
such	O
as	O
a	O
television	O
,	O
typically	O
using	O
modems	O
to	O
send	O
data	O
in	O
both	O
directions	O
.	O
</s>
<s>
All	O
such	O
systems	O
are	O
occasionally	O
referred	O
to	O
as	O
viewdata	B-Application
.	O
</s>
<s>
Unlike	O
the	O
modern	O
Internet	O
,	O
traditional	O
videotex	B-Operating_System
services	O
were	O
highly	O
centralized	O
.	O
</s>
<s>
Videotex	B-Operating_System
in	O
its	O
broader	O
definition	O
can	O
be	O
used	O
to	O
refer	O
to	O
any	O
such	O
service	O
,	O
including	O
teletext	O
,	O
the	O
Internet	O
,	O
bulletin	B-Application
board	I-Application
systems	I-Application
,	O
online	O
service	O
providers	O
,	O
and	O
even	O
the	O
arrival/departure	O
displays	O
at	O
an	O
airport	O
.	O
</s>
<s>
With	O
the	O
exception	O
of	O
Minitel	B-Application
in	O
France	O
,	O
videotex	B-Operating_System
elsewhere	O
never	O
managed	O
to	O
attract	O
any	O
more	O
than	O
a	O
very	O
small	O
percentage	O
of	O
the	O
universal	O
mass	O
market	O
once	O
envisaged	O
.	O
</s>
<s>
The	O
first	O
attempts	O
at	O
a	O
general-purpose	O
videotex	B-Operating_System
service	O
were	O
created	O
in	O
the	O
United	O
Kingdom	O
in	O
the	O
late	O
1960s	O
.	O
</s>
<s>
Meanwhile	O
,	O
the	O
General	O
Post	O
Office	O
(	O
soon	O
to	O
become	O
British	O
Telecom	O
)	O
had	O
been	O
researching	O
a	O
similar	O
concept	O
since	O
the	O
late	O
1960s	O
,	O
known	O
as	O
Viewdata	B-Application
.	O
</s>
<s>
Unlike	O
Ceefax	O
which	O
was	O
a	O
one-way	O
service	O
carried	O
in	O
the	O
existing	O
TV	O
signal	O
,	O
Viewdata	B-Application
was	O
a	O
two-way	O
system	O
using	O
telephones	O
.	O
</s>
<s>
Not	O
to	O
be	O
outdone	O
by	O
the	O
BBC	O
,	O
they	O
also	O
announced	O
their	O
service	O
,	O
under	O
the	O
name	O
Prestel	B-General_Concept
.	O
</s>
<s>
The	O
standard	O
did	O
not	O
define	O
the	O
delivery	O
system	O
,	O
so	O
both	O
Viewdata-like	O
and	O
Teledata-like	O
services	O
could	O
at	O
least	O
share	O
the	O
TV-side	O
hardware	O
(	O
which	O
at	O
that	O
point	O
in	O
time	O
was	O
quite	O
expensive	O
)	O
.	O
</s>
<s>
Ceefax	O
first	O
started	O
operation	O
in	O
1977	O
with	O
a	O
limited	O
30	O
pages	O
,	O
followed	O
quickly	O
by	O
ORACLE	O
and	O
then	O
Prestel	B-General_Concept
in	O
1979	O
.	O
</s>
<s>
By	O
1981	O
Prestel	B-General_Concept
International	O
was	O
available	O
in	O
nine	O
countries	O
,	O
and	O
a	O
number	O
of	O
countries	O
,	O
including	O
Sweden	O
,	O
The	O
Netherlands	O
,	O
Finland	O
and	O
West	O
Germany	O
were	O
developing	O
their	O
own	O
national	O
systems	O
closely	O
based	O
on	O
Prestel	B-General_Concept
.	O
</s>
<s>
In	O
the	O
early	O
1980s	O
videotex	B-Operating_System
became	O
the	O
base	O
technology	O
for	O
the	O
London	O
Stock	O
Exchange	O
's	O
pricing	O
service	O
called	O
TOPIC	O
.	O
</s>
<s>
A	O
very	O
simple	O
2-way	O
videotex	B-Operating_System
system	O
called	O
Tictac	O
was	O
also	O
demonstrated	O
in	O
the	O
mid-1970s	O
.	O
</s>
<s>
As	O
in	O
the	O
UK	O
,	O
this	O
led	O
on	O
to	O
work	O
to	O
develop	O
a	O
common	O
display	O
standard	O
for	O
videotex	B-Operating_System
and	O
teletext	O
,	O
called	O
Antiope	O
,	O
which	O
was	O
finalised	O
in	O
1977	O
.	O
</s>
<s>
The	O
trial	O
was	O
a	O
success	O
,	O
and	O
in	O
1982	O
Minitel	B-Application
was	O
rolled	O
out	O
nationwide	O
.	O
</s>
<s>
In	O
1975	O
,	O
the	O
CRC	O
gave	O
a	O
contract	O
to	O
Norpak	O
to	O
develop	O
an	O
interactive	O
graphics	O
terminal	B-General_Concept
that	O
could	O
decode	O
the	O
instructions	O
and	O
display	O
them	O
on	O
a	O
colour	O
display	O
,	O
which	O
was	O
successfully	O
up	O
and	O
running	O
by	O
1977	O
.	O
</s>
<s>
In	O
August	O
1978	O
the	O
Canadian	O
Department	O
of	O
Communications	O
publicly	O
launched	O
it	O
as	O
Telidon	B-Device
,	O
a	O
"	O
second	O
generation	O
"	O
videotex/teletext	O
service	O
,	O
and	O
committed	O
to	O
a	O
four-year	O
development	O
plan	O
to	O
encourage	O
rollout	O
.	O
</s>
<s>
Compared	O
to	O
the	O
European	O
systems	O
,	O
Telidon	B-Device
offered	O
real	O
graphics	O
,	O
as	O
opposed	O
to	O
block-mosaic	O
character	O
graphics	O
.	O
</s>
<s>
The	O
downside	O
was	O
that	O
it	O
required	O
much	O
more	O
advanced	O
decoders	O
,	O
typically	O
featuring	O
Zilog	B-General_Concept
Z80	I-General_Concept
or	O
Motorola	B-Device
6809	I-Device
processors	O
.	O
</s>
<s>
With	O
1970s	O
technology	O
,	O
the	O
ability	O
to	O
generate	O
of	O
so	O
many	O
characters	O
on	O
demand	O
in	O
the	O
end-user	O
'	O
s	O
terminal	B-General_Concept
was	O
seen	O
as	O
prohibitive	O
.	O
</s>
<s>
This	O
led	O
to	O
a	O
videotex	B-Operating_System
system	O
called	O
Captain	O
(	O
"	O
Character	O
and	O
Pattern	O
Telephone	O
Access	O
Information	O
Network	O
"	O
)	O
,	O
created	O
by	O
NTT	O
in	O
1978	O
,	O
which	O
went	O
into	O
full	O
trials	O
from	O
1979	O
to	O
1981	O
.	O
</s>
<s>
Work	O
to	O
establish	O
an	O
international	O
standard	O
for	O
videotex	B-Operating_System
began	O
in	O
1978	O
in	O
CCITT	O
.	O
</s>
<s>
This	O
was	O
closely	O
based	O
on	O
the	O
Canadian	O
Telidon	B-Device
system	O
,	O
but	O
added	O
to	O
it	O
some	O
further	O
graphics	O
primitives	O
and	O
a	O
syntax	O
for	O
defining	O
macros	O
,	O
algorithms	O
to	O
define	O
cleaner	O
pixel	O
spacing	O
for	O
the	O
(	O
arbitrarily	O
sizeable	O
)	O
text	O
,	O
and	O
also	O
dynamically	O
redefinable	O
characters	O
and	O
a	O
mosaic	O
block	O
graphic	O
character	O
set	O
,	O
so	O
that	O
it	O
could	O
reproduce	O
content	O
from	O
the	O
French	O
Antiope	O
.	O
</s>
<s>
After	O
some	O
further	O
revisions	O
this	O
was	O
adopted	O
in	O
1983	O
as	O
ANSI	O
standard	O
X3.110	O
,	O
more	O
commonly	O
called	O
NAPLPS	B-Protocol
,	O
the	O
North	O
American	O
Presentation	O
Layer	O
Protocol	O
Syntax	O
.	O
</s>
<s>
Meanwhile	O
,	O
the	O
European	O
national	O
Postal	O
Telephone	O
and	O
Telegraph	O
(	O
PTT	O
)	O
agencies	O
were	O
also	O
increasingly	O
interested	O
in	O
videotex	B-Operating_System
,	O
and	O
had	O
convened	O
discussions	O
in	O
European	O
Conference	O
of	O
Postal	O
and	O
Telecommunications	O
Administrations	O
(	O
CEPT	O
)	O
to	O
co-ordinate	O
developments	O
,	O
which	O
had	O
been	O
diverging	O
along	O
national	O
lines	O
.	O
</s>
<s>
As	O
well	O
as	O
the	O
British	O
and	O
French	O
standards	O
,	O
the	O
Swedes	O
had	O
proposed	O
extending	O
the	O
British	O
Prestel	B-General_Concept
standard	O
with	O
a	O
new	O
set	O
of	O
smoother	O
mosaic	O
graphics	O
characters	O
;	O
while	O
the	O
specification	O
for	O
the	O
proposed	O
German	O
Bildschirmtext	O
(	O
BTX	O
)	O
system	O
,	O
developed	O
under	O
contract	O
by	O
IBM	O
Germany	O
for	O
Deutsche	O
Bundespost	O
,	O
was	O
growing	O
increasingly	O
baroque	O
.	O
</s>
<s>
Originally	O
conceived	O
to	O
follow	O
the	O
UK	O
Prestel	B-General_Concept
system	O
,	O
it	O
had	O
accreted	O
elements	O
from	O
all	O
the	O
other	O
European	O
standards	O
and	O
more	O
.	O
</s>
<s>
This	O
became	O
the	O
basis	O
for	O
setting	O
out	O
the	O
CEPT	B-Device
recommendation	I-Device
T/CD	I-Device
06-01	I-Device
,	O
also	O
proposed	O
in	O
May	O
1981	O
.	O
</s>
<s>
CEPT1	B-Device
,	O
corresponding	O
to	O
the	O
German	O
BTX	O
;	O
</s>
<s>
CEPT2	B-Device
,	O
the	O
French	O
Minitel	B-Application
;	O
</s>
<s>
CEPT3	B-Device
,	O
the	O
British	O
Prestel	B-General_Concept
;	O
</s>
<s>
CEPT4	B-Device
,	O
the	O
Swedish	O
Prestel	B-General_Concept
Plus	O
.	O
</s>
<s>
National	O
videotex	B-Operating_System
services	O
were	O
encouraged	O
to	O
follow	O
one	O
of	O
the	O
existing	O
four	O
basic	O
profiles	O
;	O
or	O
if	O
they	O
extended	O
them	O
,	O
to	O
do	O
so	O
in	O
ways	O
compatible	O
with	O
a	O
"	O
harmonised	O
enhanced	O
"	O
specification	O
.	O
</s>
<s>
There	O
was	O
talk	O
of	O
upgrading	O
Prestel	B-General_Concept
to	O
the	O
full	O
CEPT	O
standard	O
"	O
within	O
a	O
couple	O
of	O
years	O
"	O
.	O
</s>
<s>
The	O
German	O
BTX	O
eventually	O
established	O
CEPT1	B-Device
;	O
the	O
French	O
Minitel	B-Application
continued	O
with	O
CEPT2	B-Device
,	O
which	O
was	O
ready	O
to	O
roll	O
out	O
;	O
and	O
the	O
British	O
stayed	O
with	O
CEPT3	B-Device
,	O
by	O
now	O
too	O
established	O
to	O
break	O
compatibility	O
.	O
</s>
<s>
In	O
later	O
years	O
CEPT	O
fixed	O
a	O
number	O
of	O
standards	O
for	O
extension	O
levels	O
to	O
the	O
basic	O
service	O
:	O
for	O
photographic	O
images	O
(	O
based	O
on	O
JPEG	O
;	O
T/TE	O
06-01	O
,	O
later	O
revisions	O
)	O
,	O
for	O
alpha-geometric	O
graphics	O
,	O
similar	O
to	O
NAPLPS/Telidon	O
(	O
T/TE	O
06-02	O
)	O
,	O
for	O
transferring	O
larger	O
data	O
files	O
and	O
software	O
(	O
T/TE	O
06-03	O
)	O
,	O
for	O
active	O
terminal-side	O
capabilities	O
and	O
scripting	O
(	O
T/TE	O
06-04	O
)	O
,	O
and	O
for	O
discovery	O
of	O
terminal	B-General_Concept
capabilities	O
(	O
T/TE	O
06-05	O
)	O
.	O
</s>
<s>
ISO-IR	O
registered	O
character	O
sets	O
for	O
Videotex	B-Operating_System
use	O
include	O
variants	O
of	O
T.51	O
,	O
semigraphic	B-Data_Structure
mosaic	O
sets	O
,	O
specialised	O
C0	O
control	O
codes	O
,	O
and	O
four	O
sets	O
of	O
specialised	O
C1	O
control	O
codes	O
.	O
</s>
<s>
Prestel	B-General_Concept
was	O
somewhat	O
popular	O
for	O
a	O
time	O
,	O
but	O
never	O
gained	O
anywhere	O
near	O
the	O
popularity	O
of	O
Ceefax	O
.	O
</s>
<s>
This	O
may	O
have	O
been	O
due	O
primarily	O
to	O
the	O
relatively	O
low	O
penetration	O
of	O
suitable	O
hardware	O
in	O
British	O
homes	O
,	O
requiring	O
the	O
user	O
to	O
pay	O
for	O
the	O
terminal	B-General_Concept
(	O
today	O
referred	O
to	O
as	O
a	O
set-top	O
box	O
)	O
,	O
a	O
monthly	O
charge	O
for	O
the	O
service	O
,	O
and	O
phone	O
bills	O
on	O
top	O
of	O
that	O
(	O
unlike	O
the	O
US	O
,	O
local	O
calls	O
were	O
paid	O
for	O
in	O
most	O
of	O
Europe	O
at	O
that	O
time	O
)	O
.	O
</s>
<s>
A	O
closed	O
access	O
videotex	B-Operating_System
system	O
based	O
on	O
the	O
Prestel	B-General_Concept
model	O
was	O
developed	O
by	O
the	O
travel	O
industry	O
,	O
and	O
continues	O
to	O
be	O
almost	O
universally	O
used	O
by	O
travel	O
agents	O
throughout	O
the	O
country	O
.	O
</s>
<s>
Using	O
a	O
prototype	O
domestic	O
television	O
equipped	O
with	O
the	O
Prestel	B-General_Concept
chip	O
set	O
,	O
Michael	O
Aldrich	O
of	O
Redifon	O
Computers	O
Ltd	O
demonstrated	O
a	O
real-time	O
transaction	O
processing	O
in	O
1979	O
or	O
online	O
shopping	O
as	O
it	O
is	O
now	O
called	O
.	O
</s>
<s>
Before	O
the	O
IBM	B-Device
PC	I-Device
,	O
Microsoft	B-Application
MS-DOS	I-Application
and	O
the	O
Internet	O
or	O
World	O
Wide	O
Web	O
,	O
he	O
invented	O
and	O
manufactured	O
and	O
sold	O
the	O
'	O
Teleputer	O
 '	O
,	O
a	O
PC	O
that	O
communicated	O
using	O
its	O
Prestel	B-General_Concept
chip	O
set	O
.	O
</s>
<s>
The	O
Teleputer	O
1	O
was	O
a	O
very	O
simple	O
device	O
and	O
only	O
worked	O
as	O
a	O
teletex	O
terminal	B-General_Concept
,	O
whereas	O
the	O
Teleputer	O
3	O
was	O
a	O
Z80	B-General_Concept
based	O
microcomputer	B-Architecture
.	O
</s>
<s>
The	O
operating	O
system	O
was	O
CP/M	B-Application
or	O
a	O
proprietary	O
variant	O
CP*	O
,	O
and	O
the	O
unit	O
was	O
supplied	O
with	O
a	O
suite	O
of	O
applications	O
,	O
consisting	O
of	O
a	O
word	O
processor	O
,	O
spreadsheet	O
,	O
database	O
and	O
a	O
semi-compiled	O
basic	O
programming	O
language	O
.	O
</s>
<s>
In	O
Spain	O
the	O
system	O
was	O
provided	O
by	O
the	O
Telefónica	O
company	O
and	O
called	O
Ibertex	B-Operating_System
,	O
which	O
was	O
adopted	O
from	O
the	O
French	O
Minitel	B-Application
system	O
,	O
but	O
using	O
the	O
German	O
CEPT-1	O
standard	O
,	O
used	O
in	O
the	O
German	O
Bildschirmtext	O
.	O
</s>
<s>
In	O
Canada	O
the	O
Department	O
of	O
Communications	O
started	O
a	O
lengthy	O
development	O
program	O
in	O
the	O
late	O
1970s	O
that	O
led	O
to	O
a	O
graphical	O
"	O
second	O
generation	O
"	O
service	O
known	O
as	O
Telidon	B-Device
.	O
</s>
<s>
Telidon	B-Device
was	O
able	O
to	O
deliver	O
service	O
using	O
the	O
vertical	O
blanking	O
interval	O
of	O
a	O
TV	O
signal	O
or	O
completely	O
by	O
telephone	O
using	O
a	O
Bell	B-Device
202	I-Device
style	O
(	O
split	O
baud	O
rate	O
150/1200	O
)	O
modem	O
.	O
</s>
<s>
The	O
use	O
of	O
the	O
202	O
model	O
modem	O
,	O
rather	O
than	O
one	O
compatible	O
with	O
the	O
existing	O
DATAPAC	B-Protocol
dial-up	O
points	O
such	O
as	O
the	O
Bell	O
212	O
,	O
created	O
severe	O
limitations	O
,	O
as	O
it	O
made	O
use	O
of	O
the	O
nationwide	O
X.25	B-Protocol
packet	B-Protocol
network	I-Protocol
essentially	O
out-of-bounds	O
for	O
Telidon-based	O
services	O
.	O
</s>
<s>
NAPLPS-based	O
systems	O
(	O
Teleguide	O
)	O
were	O
also	O
used	O
for	O
an	O
interactive	O
Mall	O
directory	O
system	O
in	O
various	O
locations	O
,	O
including	O
the	O
world	O
's	O
largest	O
indoor	O
mall	O
,	O
West	O
Edmonton	O
Mall	O
(	O
1985	O
)	O
and	O
the	O
Toronto	O
Eaton	O
Center	O
.	O
</s>
<s>
One	O
of	O
the	O
earliest	O
experiments	O
with	O
marketing	O
videotex	B-Operating_System
to	O
consumers	O
in	O
the	O
U.S.	O
was	O
by	O
Radio	O
Shack	O
,	O
which	O
sold	O
a	O
consumer	O
videotex	B-Operating_System
terminal	B-General_Concept
,	O
essentially	O
a	O
single-purpose	O
predecessor	O
to	O
the	O
TRS-80	B-Device
Color	I-Device
Computer	I-Device
,	O
in	O
outlets	O
across	O
the	O
country	O
.	O
</s>
<s>
Radio	O
Shack	O
later	O
sold	O
a	O
videotex	B-Operating_System
software	O
and	O
hardware	O
package	O
for	O
the	O
Color	B-Device
Computer	I-Device
.	O
</s>
<s>
In	O
an	O
attempt	O
to	O
capitalize	O
on	O
the	O
European	O
experience	O
,	O
a	O
number	O
of	O
US-based	O
media	O
firms	O
started	O
their	O
own	O
videotex	B-Operating_System
systems	O
in	O
the	O
early	O
1980s	O
.	O
</s>
<s>
Some	O
selected	O
Telidon	B-Device
(	O
now	O
standardized	O
as	O
NAPLPS	B-Protocol
)	O
but	O
the	O
majority	O
decided	O
to	O
use	O
slight-modified	O
versions	O
of	O
the	O
Prestel	B-General_Concept
hardware	O
.	O
</s>
<s>
The	O
primary	O
problem	O
was	O
that	O
the	O
systems	O
were	O
simply	O
too	O
slow	O
,	O
operating	O
on	O
300	O
baud	O
modems	O
connected	O
to	O
large	O
minicomputers	B-Architecture
.	O
</s>
<s>
Furthermore	O
,	O
most	O
of	O
the	O
same	O
information	O
was	O
available	O
in	O
easy-to-use	O
TV	O
format	O
on	O
the	O
air	O
,	O
or	O
in	O
general	O
reference	O
books	O
at	O
the	O
local	O
library	O
,	O
and	O
did	O
n't	O
tie	O
up	O
a	O
landline	B-Application
.	O
</s>
<s>
The	O
most	O
successful	O
online	O
services	O
of	O
the	O
period	O
were	O
not	O
videotex	B-Operating_System
services	O
at	O
all	O
.	O
</s>
<s>
Despite	O
the	O
promises	O
that	O
videotex	B-Operating_System
would	O
appeal	O
to	O
the	O
mass	O
market	O
,	O
the	O
videotex	B-Operating_System
services	O
were	O
comfortably	O
out-distanced	O
by	O
Dow	O
Jones	O
News/Retrieval	O
(	O
begun	O
in	O
1973	O
)	O
,	O
CompuServe	O
and	O
(	O
somewhat	O
further	O
behind	O
)	O
The	O
Source	O
,	O
both	O
begun	O
in	O
1979	O
.	O
</s>
<s>
None	O
were	O
videotex	B-Operating_System
services	O
,	O
nor	O
did	O
they	O
use	O
the	O
fixed	O
frame-by-frame	O
videotex	B-Operating_System
model	O
for	O
content	O
.	O
</s>
<s>
Other	O
ASCII-based	O
services	O
that	O
became	O
popular	O
included	O
Delphi	O
(	O
launched	O
in	O
1983	O
)	O
and	O
GEnie	B-Language
(	O
launched	O
in	O
1985	O
)	O
.	O
</s>
<s>
Nevertheless	O
,	O
NAPLPS-based	O
services	O
were	O
developed	O
by	O
several	O
other	O
joint	O
partnerships	O
between	O
1983	O
and	O
1987	O
.	O
</s>
<s>
A	O
joint	O
venture	O
of	O
AT&	O
T-CBS	O
completed	O
a	O
moderately	O
successful	O
trial	O
of	O
videotex	B-Operating_System
use	O
in	O
the	O
homes	O
of	O
Ridgewood	O
,	O
New	O
Jersey	O
,	O
leveraging	O
technology	O
developed	O
at	O
Bell	O
Labs	O
.	O
</s>
<s>
Around	O
1985	O
,	O
this	O
entity	O
began	O
to	O
offer	O
a	O
service	O
called	O
Prodigy	O
,	O
which	O
used	O
NAPLPS	B-Protocol
to	O
send	O
information	O
to	O
its	O
users	O
,	O
right	O
up	O
until	O
it	O
turned	O
into	O
an	O
Internet	O
service	O
provider	O
in	O
the	O
late	O
1990s	O
.	O
</s>
<s>
Because	O
of	O
its	O
relatively	O
late	O
debut	O
,	O
Prodigy	O
was	O
able	O
to	O
skip	O
the	O
intermediate	O
step	O
of	O
persuading	O
American	O
consumers	O
to	O
attach	O
proprietary	O
boxes	O
to	O
their	O
televisions	O
;	O
it	O
was	O
among	O
the	O
earliest	O
proponents	O
of	O
computer-based	O
videotex	B-Operating_System
.	O
</s>
<s>
Videotex	B-Operating_System
technology	O
was	O
also	O
adopted	O
for	O
use	O
internally	O
within	O
organizations	O
.	O
</s>
<s>
Digital	O
Equipment	O
Corp	O
(	O
DEC	O
)	O
offered	O
a	O
videotex	B-Operating_System
product	O
(	O
VTX	O
)	O
on	O
the	O
VAX	O
system	O
.	O
</s>
<s>
One	O
of	O
the	O
earliest	O
corporations	O
to	O
participate	O
in	O
videotex	B-Operating_System
in	O
the	O
United	O
States	O
was	O
American	O
Express	O
.	O
</s>
<s>
Australia	O
's	O
national	O
public	O
Videotex	B-Operating_System
service	O
,	O
Viatel	O
,	O
was	O
launched	O
by	O
Telecom	O
Australia	O
on	O
28	O
February	O
1985	O
.	O
</s>
<s>
It	O
was	O
based	O
on	O
the	O
British	O
Prestel	B-General_Concept
service	O
.	O
</s>
<s>
In	O
the	O
Netherlands	O
the	O
then	O
state-owned	O
phone	O
company	O
PTT	O
(	O
now	O
KPN	O
)	O
operated	O
two	O
platforms	O
:	O
Viditel	O
(	O
launched	O
in	O
1980	O
)	O
and	O
Videotex	B-Operating_System
Nederland	O
.	O
</s>
<s>
From	O
the	O
user	O
perspective	O
the	O
main	O
difference	O
between	O
these	O
systems	O
was	O
that	O
Viditel	O
used	O
standard	O
dial-in	O
phone	O
numbers	O
where	O
Videotex	B-Operating_System
used	O
premium-rate	O
telephone	O
numbers	O
.	O
</s>
<s>
For	O
Videotex	B-Operating_System
services	O
you	O
normally	O
did	O
n't	O
need	O
a	O
subscription	O
nor	O
was	O
there	O
the	O
need	O
to	O
authenticate	O
:	O
you	O
paid	O
for	O
the	O
services	O
via	O
the	O
premium	O
rate	O
of	O
the	O
modem-connection	O
based	O
on	O
connection	O
time	O
,	O
regardless	O
of	O
the	O
pages	O
or	O
services	O
you	O
retrieved	O
.	O
</s>
<s>
From	O
the	O
information-provider	O
point	O
of	O
view	O
there	O
were	O
huge	O
differences	O
between	O
Viditel	O
and	O
Videotex	B-Operating_System
:	O
Via	O
Viditel	O
all	O
data	O
was	O
normally	O
stored	O
on	O
the	O
central	O
computer(s )	O
owned	O
and	O
managed	O
by	O
KPN	O
:	O
to	O
update	O
the	O
information	O
in	O
the	O
system	O
you	O
connected	O
to	O
the	O
Viditel	O
computer	O
and	O
via	O
a	O
terminal-emulation	O
application	O
you	O
could	O
edit	O
the	O
information	O
.	O
</s>
<s>
But	O
when	O
using	O
Videotex	B-Operating_System
the	O
information	O
is	O
on	O
a	O
computer-platform	O
owned	O
and	O
managed	O
by	O
the	O
information-provider	O
.	O
</s>
<s>
The	O
Videotex	B-Operating_System
system	O
connected	O
the	O
end-user	O
to	O
the	O
Datanet	O
1	O
line	O
of	O
the	O
information-provider	O
.	O
</s>
<s>
It	O
was	O
up	O
to	O
the	O
information	O
provider	O
if	O
the	O
access-point	O
(	O
the	O
box	O
directly	O
behind	O
the	O
telephone	O
line	O
)	O
supported	O
the	O
videotex	B-Operating_System
protocol	O
or	O
that	O
it	O
was	O
a	O
transparent	O
connection	O
where	O
the	O
host	O
handled	O
the	O
protocol	O
.	O
</s>
<s>
As	O
said	O
the	O
Videotex	B-Operating_System
Nederland	O
services	O
offered	O
access	O
via	O
several	O
primary	O
rate	O
numbers	O
and	O
the	O
information/service	O
provider	O
could	O
choose	O
the	O
costs	O
for	O
accessing	O
his	O
service	O
.	O
</s>
<s>
The	O
network	O
of	O
Videotex	B-Operating_System
Nederland	O
offered	O
also	O
direct	O
access	O
to	O
most	O
services	O
of	O
the	O
French	O
minitel	B-Application
system	O
.	O
</s>
<s>
A	O
version	O
of	O
the	O
French	O
Minitel	B-Application
system	O
was	O
introduced	O
to	O
Ireland	O
by	O
eircom	O
(	O
then	O
called	O
Telecom	O
Éireann	O
)	O
in	O
1988	O
.	O
</s>
<s>
It	O
was	O
n't	O
a	O
centralised	O
service	O
and	O
individual	O
service	O
providers	O
could	O
connect	O
to	O
it	O
via	O
the	O
Eirpac	B-Protocol
packet	B-Protocol
switching	I-Protocol
network	O
.	O
</s>
<s>
It	O
could	O
also	O
connect	O
to	O
databases	O
on	O
other	O
networks	O
such	O
as	O
French	O
Minitel	B-Application
services	O
,	O
European	O
databases	O
and	O
university	O
systems	O
.	O
</s>
<s>
The	O
rise	O
of	O
the	O
internet	O
and	O
other	O
global	O
online	O
services	O
in	O
the	O
early	O
to	O
mid-1990s	O
played	O
a	O
major	O
factor	O
in	O
the	O
death	O
of	O
Irish	O
Minitel	B-Application
.	O
</s>
<s>
Minitel	B-Application
Ireland	O
's	O
terminals	O
were	O
technically	O
identical	O
to	O
their	O
French	O
counterparts	O
,	O
except	O
that	O
they	O
had	O
a	O
QWERTY	O
keyboard	O
and	O
an	O
RJ-11	O
telephone	O
jack	O
which	O
is	O
the	O
standard	O
telephone	O
connector	O
in	O
Ireland	O
.	O
</s>
<s>
With	O
the	O
French	O
Minitel	B-Application
system	O
,	O
unlike	O
any	O
other	O
service	O
,	O
the	O
users	O
were	O
given	O
an	O
entire	O
custom	O
designed	O
terminal	B-General_Concept
for	O
free	O
.	O
</s>
<s>
This	O
was	O
a	O
deliberate	O
move	O
on	O
the	O
part	O
of	O
France	O
Telecom	O
,	O
which	O
reasoned	O
that	O
it	O
would	O
be	O
cheaper	O
in	O
the	O
long	O
run	O
to	O
give	O
away	O
free	O
terminals	O
and	O
teach	O
its	O
customers	O
how	O
to	O
look	O
up	O
telephone	O
listings	O
on	O
the	O
terminal	B-General_Concept
,	O
instead	O
of	O
continuing	O
to	O
print	O
and	O
ship	O
millions	O
of	O
phone	O
books	O
each	O
year	O
.	O
</s>
<s>
Like	O
Prestel	B-General_Concept
,	O
Minitel	B-Application
used	O
an	O
asymmetric	O
modem	O
(	O
1200-bit/s	O
for	O
downloading	O
information	O
to	O
the	O
terminal	B-General_Concept
and	O
75-bit/s	O
back	O
)	O
.	O
</s>
<s>
Bell	O
Canada	O
introduced	O
Minitel	B-Application
to	O
Quebec	O
as	O
Alex	O
in	O
1988	O
,	O
and	O
Ontario	B-Architecture
two	O
years	O
later	O
.	O
</s>
<s>
It	O
was	O
available	O
both	O
as	O
a	O
standalone	O
CRT	B-Device
terminal	B-General_Concept
(	O
very	O
similar	O
in	O
design	O
to	O
the	O
ADM-3A	B-Device
)	O
with	O
1200-bit/s	O
modem	O
,	O
and	O
as	O
software-only	O
for	O
MS-DOS	B-Application
computers	O
.	O
</s>
<s>
The	O
Alex	O
terminals	O
did	O
double	O
duty	O
for	O
connecting	O
to	O
text-only	O
BBSes	B-Application
.	O
</s>
<s>
While	O
some	O
people	O
consider	O
videotex	B-Operating_System
to	O
be	O
the	O
precursor	O
of	O
the	O
Internet	O
,	O
the	O
two	O
technologies	O
evolved	O
separately	O
and	O
reflect	O
fundamentally	O
different	O
assumptions	O
about	O
how	O
to	O
computerize	O
communications	O
.	O
</s>
<s>
In	O
contrast	O
,	O
videotex	B-Operating_System
was	O
always	O
highly	O
centralized	O
(	O
except	O
in	O
the	O
French	O
Minitel	B-Application
service	O
,	O
also	O
including	O
thousands	O
of	O
information	O
providers	O
running	O
their	O
own	O
servers	O
connected	O
to	O
the	O
packet	B-Protocol
switched	I-Protocol
network	I-Protocol
"	O
TRANSPAC	O
"	O
)	O
.	O
</s>
<s>
Even	O
in	O
videotex	B-Operating_System
networks	O
where	O
third-party	O
companies	O
could	O
post	O
their	O
own	O
content	O
and	O
operate	O
special	O
services	O
like	O
forums	O
,	O
a	O
single	O
company	O
usually	O
owned	O
and	O
operated	O
the	O
underlying	O
communications	O
network	O
,	O
developed	O
and	O
deployed	O
the	O
necessary	O
hardware	O
and	O
software	O
,	O
and	O
billed	O
both	O
content	O
providers	O
and	O
users	O
for	O
access	O
.	O
</s>
<s>
The	O
exception	O
was	O
the	O
transaction	O
processing	O
videotex	B-Operating_System
system	O
developed	O
in	O
the	O
UK	O
by	O
Michael	O
Aldrich	O
in	O
1979	O
,	O
which	O
brought	O
teleshopping	O
(	O
or	O
online	O
shopping	O
as	O
it	O
was	O
later	O
called	O
)	O
into	O
prominence	O
and	O
was	O
the	O
idea	O
developed	O
later	O
through	O
the	O
Internet	O
.	O
</s>
<s>
Aldrich	O
's	O
systems	O
were	O
based	O
on	O
minicomputers	B-Architecture
that	O
could	O
communicate	O
with	O
multiple	O
mainframes	O
.	O
</s>
<s>
Nearly	O
all	O
books	O
and	O
articles	O
(	O
in	O
English	O
)	O
from	O
videotex	B-Operating_System
's	O
heyday	O
(	O
the	O
late	O
1970s	O
and	O
early	O
1980s	O
)	O
seem	O
to	O
reflect	O
a	O
common	O
assumption	O
that	O
in	O
any	O
given	O
videotex	B-Operating_System
system	O
,	O
there	O
would	O
be	O
a	O
single	O
company	O
that	O
would	O
build	O
and	O
operate	O
the	O
network	O
.	O
</s>
<s>
At	O
the	O
time	O
,	O
AT&T	O
did	O
not	O
take	O
seriously	O
the	O
threat	O
posed	O
by	O
packet	B-Protocol
switching	I-Protocol
;	O
it	O
actually	O
turned	O
down	O
the	O
opportunity	O
to	O
take	O
over	O
ARPANET	O
.	O
</s>
<s>
Other	O
computer	O
networks	O
at	O
the	O
time	O
were	O
not	O
really	O
decentralized	O
;	O
for	O
example	O
,	O
the	O
private	O
network	O
Tymnet	B-Application
had	O
central	O
control	O
computers	O
called	O
supervisors	O
which	O
controlled	O
each	O
other	O
in	O
an	O
automatically	O
determined	O
hierarchy	O
.	O
</s>
<s>
Definitions	O
of	O
Videotex	B-Operating_System
and	O
associated	O
terms	O
.	O
</s>
<s>
Videotex	B-Operating_System
:	O
A	O
two-way	O
interactive	O
service	O
.	O
</s>
<s>
Viewdata	B-Application
:	O
An	O
alternative	O
term	O
to	O
videotex	B-Operating_System
,	O
used	O
in	O
particular	O
by	O
the	O
British	O
Post	O
Office	O
and	O
generally	O
in	O
Britain	O
and	O
the	O
USA	O
.	O
</s>
<s>
Elsewhere	O
,	O
the	O
term	O
videotex	B-Operating_System
is	O
preferred	O
.	O
</s>
<s>
Viewdata	B-Application
was	O
coined	O
by	O
the	O
BPO	O
in	O
the	O
early	O
1970s	O
,	O
but	O
found	O
to	O
be	O
unacceptable	O
as	O
a	O
trade	O
name	O
,	O
hence	O
its	O
use	O
as	O
a	O
generic	O
.	O
</s>
<s>
Compared	O
with	O
two-way	O
videotex	B-Operating_System
,	O
teletext	O
is	O
inherently	O
more	O
limited	O
,	O
though	O
generally	O
less	O
costly	O
.	O
</s>
<s>
Bildschirmtext	O
,	O
DataVision	O
,	O
Bulletin	O
,	O
Captain	O
,	O
Teletel	B-Application
,	O
Prestel	B-General_Concept
,	O
Viewtron	O
,	O
etc	O
.	O
</s>
<s>
:	O
The	O
proprietary	O
names	O
for	O
specific	O
videotex	B-Operating_System
implementations	O
.	O
</s>
