View RSS Feed

UK Mike (miner2049er)

The Prestel System

Rate this Entry
The first gaming system I ever got was a Prestel machine, so let's look at the Prestel and see what the system was all about

We got our prestel around 1979 when they were first commercially launched in the UK having been in development since the early 70s.

The name Prestel is an abbreviation for Press Telephone which is the brand name for the UK Post Office's Viewdata technology.

Basically it was what's called an interactive videotex system that used a modified television set to display information in a non scrolling, fixed screen of 40x24 text characters but it could also display simple graphics using blocks of colour.

A Prestel TV set looks and works just like any other tv set but it has an extra 12 control buttons and its connected to the telephone line.

Prestel was similar to the BBC Ceefax and ITV Oracle Teletext services that you could get through your normal tv but unlike the limited data on those text services Prestel gave you more information that came from both the Prestel department of the Post Office and from third-party Providers including Government agencies.

So for our American audience and any others that may not be familiar with a Teletext service what is it?

Well, Teletext is a service provided b y television companies and you access it via your TV set and TV remote control.

It is probably easiest if you think of it in terms of the modern internet but only using basic text characters and block graphics.

To access it you would press the Teletext button on your TV remote and the main page would come up on screen. On that main page you would several options such as TV Guide 100, sport 300 travel 400 news 500.

Now if you key in on your remote the number 100 the TV guide page will appear or if you key in 500 the news page will appear. Now you may have the option to go national news on 520 or international on 520 and so on.

If for example you are interested in sport, and the sport is on 300, there will be a sub menu for different sports, so football may be on 310, motorsport on 320, rugby on 330 etc.

Next time you use Teletext, if you know the page you want such as rugby headlines you would go direct to that page by keying in 330 or 331 for the first headline and 332 for the second headline etc.

In addition to using the number keys, a development of teletext brought about the colour key options. Listed at the bottom of the page like a footer would be 4 options, usually key options in different colours such as news in red, sport in blue, politics in green and TV in yellow.

Looking at your remote you would have 4 coloured buttons, so if you wanted to jump straight to the politics page, instead of keying in its 3 digit code you could just hit the green button and go straight to it.

The whole thing works in a very simlar way to the internet with erach page having a unique address and containing links to other pages, but there afre also favourite pages whose numbers, or addresses you remember and you can go straight to them as though using bookmarks.

Since all Prestel pages were numbered, once you had used an index to locate specific information, you could repeatedly go back to selected pages with a direct call to the individual page numbers. This ability to jump from any part of the Prestel database to any other part in less than two seconds was not only a time saver but was also a much cheaper option too.

Sam Fedida, a Computer Applications Manager for the British Post Office Research Laboratories was acknowledged as the inventor of the system.

The first public demonstration was in late 1974 on a Hewlett-Packard minicomputer. Its commercial launch was in early 1979 and ironically it was Fedida's son Clive, a British Telecom executive that was instrumental in closing the service in the spring of 1994.

The provider end of the Prestel system consisted of a central Update Computer known as "Duke" which was located in London, and then that content was mirrored onto a number of satellite computers that were called things like "Dryden", "Kipling", "Derwent", "Enterprise", "Dickens", "Keats", "Bronte", "Eliot" and "Austen" and these satellite computers were located all around the country. The electronic mail part of the service was handled by a machine known as "Pandora" and all of these machines, the central; update computer, the satellites and the mail provider were GEC 4000 series computers.

Access to Prestel was open to everybody except for a small number of Closed User Groups that usually charged a subscription fee to join.

While the BBC Ceefax and ITV Oracle Teletext services were free and encoded as part of the regular television transmissions, Prestel data was transmitted via the telephone system to a set-top box like terminal that enabled two way communication so you could have interactive services and even a basic form of e-mail.

Obviously this involved buying a suitable terminal, paying a monthly subscription and paying the cost of local telephone calls for the data which made it an expensive pastime, and on top of this, some services like Micronet800 sold content on a paid-for basis.

Each Prestel screen that was displayed showed a price in pence in the top right-hand corner and single screens would usually cost 2p but could cost as much as 99p. 99p for a single screen of 40x24 data.

Anyway, the original idea was to persuade consumers to buy a modified television set with an inbuilt modem and a keypad remote control in order to access the service, but no more than a handful of models were ever marketed and those that were, were ridiculously expensive, usually about three times the cost of a normal TV set.

Some set-top boxes were provided by companies like the Nottingham Building Society for its customers, who could use it to make financial transactions via Prestel.

What could have been the systems saving grace came in the late 1980s when the access situation improved as home computers became more popular, and by this time it was possible to use machines like the BBC Micro equipped with a modem and some simple software, to access the Prestel service.

Even the more games-orientated Sinclair ZX Spectrum had a large number of users connected via a cheap modem called the VTX-5000 and you could use Prestel to buy downloadable content such as simple games.

These games would be encoded in a series of single pages that were encoded in blocks of less than 1 kilobyte at a time. The pages themselves weren't readable but the header and footer were so users could watch the pages appearing one after another as they built up the complete downloaded file.

To charge for these games the final pages of the download were charged at 99p each until the total charged came within 99p of the total price, then one page would be charged at the balance of the total price, so if the game was £5.63 you would get 5 pages charged at 99p and then one charged at 64p then any subsequent pages were free.

Because the communication over telephone lines didn't use any kind of error correction protocol it was prone to interference from line noise that could either corrupt your donwload or give you garbled text.

In 1984 Prestel won a UK Queen's Award for Industry both for its innovative technology and use of British products but ironically the 1984 hacker intrusion into the (very likely unused) Prestel mailbox of the Duke of Edinburgh garnered the network some unfavourable press, particularly when the simplicity of its security measures became apparent. The subsequent failure to successfully prosecute the intruders contributed to the introduction of the Computer Misuse Act 1990.

Despite the fact that you could now use computers to access the system, Prestel was still an expensive hobby, and as a result it only ever gained a limited market penetration among private consumers reaching a peak of just 90,000 subscribers, with the largest user groups being Micronet800 with 20,000 users and Prestel Travel with 6,500 users.

Not deterred by the poor figures though, the BT Prestel software development team made a number of prestel variants, all of which still ran on GEC Computers, and sold them to the phone companies of foreign countries including Austria, Belgium, Italy, Hungary, Hong Kong and Singapore among others.

The largest of these foreign systems was Italy with 180,000 subscribers.

The Singapore system was technologically different because the pages weren't delivered over the modem connection, they were sent using teletext methods over one of four TV channels that were reserved for Prestel. This higher bandwidth meant that higher resolution pictures could be used unlike other standard Prestel systems.

In 1990, BT introduced a new commercial model that pretty much killed off the domestic Prestel service and finally in 1991 BT decided to move away from providing Value Added Services and turn its mind to focusing on their network provision.

Obviously the various consumer and business services were either run down or sold off so that services like Prestel Travel and the BT Insurance Service became private network services.

In 1994 the Prestel name and equipment was eventually sold by BT to a private company called Financial Express and renamed the New Prestel.

The platform software was redeveloped onto a Unix and Linux platform and moved away from the massive mainframes that it had been run from before.

Prestel Online, which was an Internet service provider spinoff, was sold to Scottish Telecom, and in June 2002 was merged with their other ISP facilities and as the Internet gathered momentum and became more popular the Prestel dial-up ViewData service was taken offline.

As the British system was wound down the the French equivalent called Teletel / Minitel went from strength to strength when millions of Minitel terminals were handed out free to telephone subscribers. Obviously that made the Teletel network very popular in France and it is still well used with access now also possible over the Internet.

The chances are that you've seen a Prestel system in good working order but just didn’t realise it. Ever booked a holiday in a travel agent's office? Seen them search online for flights and accomodation? The system they use is a closed access videotex system based on Prestel.
Some people thought it was a system ahead of its time but others think it was just an expensive research toy with little or no commercial value but at the time it was the world's largest computerised information service and up until January 1982, an extensive printed directory of the Prestel database was available on a quarterly basis from the Financial Times in London.

For American Prestel users there were three types of charges on Prestel. The first was a $50 per month membership fee. This is not a minimum use charge, but a flat fee added to all time and page charges. Second, there was a charge for connect time: 30 cents a minute if you didn't use Telenet or 45 cents a minute if you did access Prestel through Telenet. This rate applied any time of day or night, 300 or 1200 bps. a third charge was the frame charge. Some information providers charged you to read their pages. If you accessed these pages from a menu page, you would be told the charges before you called up a page. These charges could run from one cent to one dollar with the average being 10-20 cents.

A way for American users to access Prestel via computer was using something like the Apple II or an IBM PC with a 212 modem and stand-alone terminals were available too from Zenith, Bishopsgate, Sony and Wolfdata.

So, what are my memories of the Prestel that we had?

Well, it arrived in the house in 1979 and we had never seen anything like it before.

I remember setting it up for the first time not even having a clue what it was, I'd never even heard of it until I saw it, but using it was magical, memories are something close to an iconic image of a young child sat in front of the glow of the TV set, mesmerised by what was unfolding on screen. That was my introduction to video games and in some ways technology too, and I've never looked back since.

Submit "The Prestel System" to Digg Submit "The Prestel System" to Submit "The Prestel System" to StumbleUpon Submit "The Prestel System" to Google

Tags: None Add / Edit Tags


Retro Gaming RoundUp