you could in fact quite legally broadcast a teletext signal from a small
transmitter if you are capable of building one, you MUST be careful however
to make sure that you get no spurious emissions and also dont use an aerial
but a coax feeder between the tx and the tuner. (IE link it up exactly as
you would a TV).
I also have a program somewhere that ran on an RML 580Z that I wrote at
school to simulate a teletext server and just made up the pages from text
files and displayed them on the screen. it was written for a school message
system above reception.
If I get time some day I'll try and dig up the disk (if it still is
readable) and zip it up and put it up somewhere.
regards
charles
----- Original Message -----
From: "Jules Richardson" <julesrichardsonuk(a)yahoo.co.uk>
To: <bbc-micro(a)cloud9.co.uk>
Sent: Sunday, September 19, 2004 2:24 PM
Subject: Re: [BBC-Micro] CEEFAX short story contest
On Sat, 2004-09-18 at 22:20 +0100, gARetH baBB wrote:
On Sat, 11 Sep 2004, Jules Richardson wrote:
BBC was? I still have a pet project to get a real
service up and
running
at the museum (and if a phone exchange can be simulated, then it's not
like we don't have plenty of old modem hardware lying around - acoustic
coupler, anyone?)
Q: what do you think viewdata has in connection with teletext (apart from
most of the display attributes) ?
Both are examples of early information retrieval systems; the problem
with a museum exhibit being that it'd be somewhat illegal to broadcast
teletext over the airwaves!
That doesn't stop the simulation using a service such as pip that I
mentioned earlier (which digging around appears to have been public-
access) across a dial-up link, though.
From a display point of view it'd make sense
to combine it with a
viewdata system (in the sense that one or the other could be
used at a
time by a terminal of some form - whether a BBC or whatever) simply to
avoid duplication of cabling, modems etc.
And an example of a BBS would be a third option of course. It's a case
of making a modem think it was talking to a phone exchange and I'm not
sure what's involved there - but the Colossus guys know all about phone
equipment and have piles of period hardware lying about so I'm sure they
can offer help.
I'm still not sure what was used server-side to construct and hold
teletext pages either (fro BBC's Ceefax or others); likely a DEC mini of
some sort - BBC machines for page composition?
cheers
Jules