On-the-spot coverage
Martin Cooper finds micros hard at work at the BBC
PORTABLE micros seem to be quite the thing these days, especially
now that Sir Clive has entered the field with his battery-powered
Z88.
In journalistic circles, lapheld LCD screen machines are becoming
commonplace. Pressrooms used to echo with the voices of reporters
yelling down the phone. Now they are filled with the tack-a-tack
of keyboards as correspondents bash out their copy on Tandys.
Rather surprising then, that the BBC Micro is also an increasingly
common sight — complete with full-sized monitor, disc drives,
modem and a tangle of wires.
The journalist at the keyboard is likely to be a sub-editor
from Ceefax.
BBC Micros are the key to the on-the-spot coverage that Ceefax
is providing from more and more events. They have been used to
report on the British Open from Turnberry in Scotland, on the
RAC Rally from Bath and on the Embassy World Snooker Championships
from the Crucible in Sheffield.
At the Commonwealth Games in Edinburgh and at Wimbledon three
or four BBC Micros were in constant use.
The journalists covering these events are not just sending material
back to the newsroom. They are using the micros as editing terminals
linked to the main Ceefax computer at Television Centre in London
and broadcasting pages "live" to 14 million viewers
all over the country.
Duty editor Graham Norwood recently returned from Dublin, where
he was covering that well-known sporting event, the Irish general
election.
"There's no doubt that we're the envy of other journalists
on these occasions", he says. "We can broadcast our
pages so easily — without masses of equipment and large camera
crews, or interminable phone calls back to the office . . ."
Mode 7 is what makes all this possible. When Acorn's Proton
was transmuted into the Models A and B, the BBC specified that
a teletext display option should be built in.
This was done with an eye to future developments in telesoftware,
but it was not long before someone realised that the micros could
be used to create as well as receive teletext pages.
At the time, state-of-the-art editing terminals were bulky and
expensive. In most cases they consisted of a purpose-built keyboard
and a cabinet full of printed circuit boards. They were troublesome
to transport and set up and cost so much that sending two terminals
to an outside event (one as backup) seriously reduced the equipment
available in the main newsroom.
The BBC Micro, on the other hand, was comparatively cheap, easily
ferried around in the boot of a car and capable of reproducing
all the requirements of broadcast teletext - including a couple
of control characters not documented in the User Guide.
Codes 138 and 139, listed as "nothing", actually punch
"boxes" in the TV picture to allow subtitles to show
through — not a lot of use to most micro users.
A BBC engineer wrote a rom-based terminal package which he called
MicroFax. From then on, with a small pool of BBC Bs, Ceefax was
on the road.
Communication between a BBC Micro and the main Ceefax computer
(a DEC PDP11) is via the RS423 port, at 9600 baud if the micro
is in the newsroom -where a modem is not needed - otherwise at
1200 baud.
Ceefax, like the rest of the BBC, uses specially-leased four-wire
British Telecom circuits to carry data around the country, rather
than the public telephone network. These have the advantages of
being noise-free and off limits to the general public, well-meaning
or otherwise.
For added security, a system of passwords defines exactly which
areas of the output each micro can access.
Working offline with MicroFax, a subeditor can store up to 20
pages in memory and save the whole 20k "magazine" on
disc. Pages can be edited or erased, merged or dumped to a printer.
Online, pages stored in memory or on disc can be uploaded in bulk
to Ceefax, and as many of the main system's facilities can be
used as password privileges allow.
MicroFax is modelled on the Aston terminals that make up most
of the newsroom's equipment. The 24 lines of the page being edited
fill most of the display, but a one-line window at the bottom
of the screen allows commands to be sent either to the micro or
to the Ceefax computer.
Text is entered in a way that will be familiar to anyone who
has used a word processor-except, of course, that there is no
scrolling.
The operator can insert and delete, or move lines up and down
the screen, but the size of the page is so limited - about 80
words - that elaborate text-handling facilities are not really
needed.
Graphics are more complicated. Dabblers in Mode 7 will know
that each of the chunky teletext graphic characters corresponds
to a letter on the keyboard.
The factor which decides whether an alphanumeric (letter) or
graphic character will be displayed is the control code preceding
it. On a teletext page these appear as blank spaces, but they
are entered from the keyboard just like any other characters.
Using MicroFax, the function keys in conjunction with Shift
and Control supply alphanumeric or graphic colour codes, other
codes, like flash and double height, are obtained with combinations
of Control and ? letter keys.
With control codes in place, MicroFax allows six keys (QWASZX)
to be used as a "graphics patch". Each switches on or
off one of six segments to define the Mode 7 graphics character
required.
"Outside broadcasts" were not the only innovation
made possible by the BBC Micro. There are several BBC Bs in the
Ceefax newsroom, where they serve as extra terminals, but other
BBC departments also have their own machines which they use to
contribute pages. Some send discs to be checked and uploaded by
Ceefax sub-editors, others go online to the main computer.
"It saves us a lot of routine inputting", says Graham
Norwood. "The BBC stand at the Ideal Home Exhibition might
have its own micro and modem, for example.
"We would give them a password which allowed access to
just one page, and they could update details of the exhibition
for themselves. Otherwise the information would probably come
to us on paper and someone here would have to type it in".
Several specialist pages are produced either by Ceefax staff
or by outside contributors working at home on their own micros.
The pop music page Ceetrax and the weekly computer "column"
Next both arrive on disc every week as MicroFax files.
Next regularly includes items written on other micros, most
commonly Spec-trums and Commodores. These are sent to the editor
via Prestel mailbox, and since Prestel shares the teletext format
they can be downloaded straight into a BBC Micro to have colour
and graphics added before being broadcast.
With so many micros around the Ceefax newsroom, it was inevitable
that someone would start programming on them.
Pages containing football fixture lists and league tables are
compiled and broadcast automatically every Saturday during the
season. The software, written in Basic by one of the sub-editors,
calls results pages from the main computer, reads the scores from
them and updates the league tables accordingly.
The whole job, which used to require half an hour of painstaking
checking, is finished in a couple of minutes.
Not all programming efforts are this successful, however. During
the last local elections one of the team came up with a short
machine code routine to count the gains and losses suffered by
each party.
The program was supposed to call up each of the results pages
in turn and check for changes. Halfway through the night it announced
its political inclinations by refusing to acknowledge any more
Conservative gains. The count was continued manually.
Ceefax Editor Graham Clayton has a BBC Micro running in his
office, though it is not linked to the main computer. He uses
a teletext adapter to keep an eye on the output from the viewers'
end. The adapter detects any updates on the channel it is tuned
to and captures the new pages for him to check through.
"With about 300 pages on BBC1 alone it would take me a
couple of hours to read them all", he explains, "and
by that time most of them would have been updated again anyway.
This is really the only way I can keep track of all the changes".
Another piece of software he uses with the adapter can carry
out a keyword search of all the pages being broadcast on the selected
channel. The search takes a single cycle of the Ceefax magazine
- currently about 15 seconds - and pages containing the keyword
are stored for immediate display.
It is not foolproof, however. A page on the latest Test match
will have a large graphics heading saying "Cricket",
which will go undetected. The text itself may well not contain
the keyword.
One of the most successful examples of an Acorn machine handling
Ceefax pages cannot be seen in this country.
In March this year a new service was launched on the French
videotex system Teletel. It consists entirely of pages taken from
Ceefax, updated several times a day.
Teletel is page-based like Prestel and Ceefax, but inevitably
the two standards are incompatible. Nevertheless, the transmission
of pages is fully automated and handled from beginning to end
by a Master 128.
The software for selecting pages and translating them into the
French standard was written by Graham Bartram, already well-known
in teletext circles as author of the ATS rom. At set intervals
during the day the Master logs on to the main Ceefax computer
and calls up a selection of pages, saving them on disc. On each
one English trail lines referring to Ceefax page numbers are replaced
by French prompts.
Periodically there is a call from France, received via an "intelligent"
auto-answer modem, and the Master reads each of its stored pages
over to a Paris-based PC, translating the characters into their
Teletel equivalents as it does so. It also sends instructions
with each page telling the French host computer where it should
be stored in the Teletel database.
The process is entirely transparent as far as the rest of Ceefax
is concerned. The main computer regards the Master simply as a
terminal, displaying pages like any other.
The BBC Micro has two disadvantages when compared with purpose-built
teletext editing terminals. The keyboard is rather restricted,
especially when it comes to graphics, and it is unable to display
the control characters which produce text colours and other effects.
The second of these two problems is probably insurmountable
(though we have all heard that one before). Most purpose-built
teletext terminals can toggle on and off a set of symbols indicating
the position of control characters.
It is difficult to see how this could be done on a micro, short
of some Elite-style juggling of modes which would greatly reduce
the memory available for offline page storage.
The keyboard problem is more easily dealt with. Ceefax and Softel,
a company specialising in teletext equipment, have been experimenting
with new casings for the BBC Micro.
The main board and two disc drives are housed in a single console,
PC-style, while a remote keyboard has been laid out with MicroFax
in mind.
The 10 function keys have been replaced by a row of 23 covering
all the control codes. The "graphics patch", meanwhile,
has been given its own block of keys, rather like the Master's
numeric keypad.
The design is still undergoing trials, but it is possible that
before long the BBC Micro — minus the familiar beige box - may
become standard equipment in teletext newsrooms.
