TELETEXT FOR KIDS!
THE SECRET PAGES HIDING IN YOUR TV
Did you know that TVs used to have SECRET PAGES hidden inside them? Not apps. Not the internet. Actual invisible information flying through the air and into your television!
It was called TELETEXT, and it was like magic. Let's find out how it worked!
WHAT WAS TELETEXT?
Imagine if your TV could show you pages - like a book - but the pages came through the air, invisibly, mixed in with the TV programmes you were watching!
That's what teletext was. You'd press a button on your remote, type in a page number (like 302 for football scores), and wait for your page to appear. It was like having a mini-internet on your telly, years before smartphones existed!
TRY IT YOURSELF!
Here's what it was like to use teletext. Use the remote control below to type in a page number, then watch the TV find your page!
WELCOME TO CEEFAX
Use the remote to explore!
Try typing: 302, 400, or 100
TIP: Try typing 302 for football scores, 400 for weather, or press the coloured buttons!
THE SCIENCE BIT: INVISIBLE LINES!
Here's where it gets really cool. Your old TV worked by drawing pictures really, really fast - 25 pictures every single second!
But here's the secret: between each picture, there was a tiny gap. The TV needed a moment to get ready for the next picture. This gap was called the VERTICAL BLANKING INTERVAL (or VBI for short).
Clever scientists thought: "What if we hide information in that gap? No one can see it, but the TV can read it!" And that's exactly what they did!
SEE HOW THE TV SCANNED EACH PICTURE:
Press the button to see how the TV's electron beam scanned from top to bottom. It read the hidden teletext data first, then drew the visible picture!
THE SPINNING PAGE CAROUSEL
Here's something wild: the TV could only send ONE page at a time! So all the pages went round and round in a loop, like a carousel at a fairground.
When you typed in a page number, your TV had to WAIT for that page to come around again. That's why it sometimes took a few seconds to load!
The pages broadcast in a loop. Select a page and wait for it to come round!
Select a page and watch the carousel spin until it comes round!
THE TIMING GAME!
Here's a game to show why timing mattered! The carousel below is always spinning. Your goal: press the button to request PAGE 316 when the carousel is as close to 316 as possible (but before it passes). The closer you time it, the faster your page loads!
Press the button when the carousel is close to (but before) 316!
AMAZING TELETEXT FACTS
- IT WAS INVENTED IN BRITAIN! - Engineers at the BBC created it in the early 1970s
- IT WAS CALLED CEEFAX - which sounds like "See Facts" - because you could see facts on your TV!
- MILLIONS OF PEOPLE USED IT - to check football scores, weather, news, and even play games!
- IT LASTED NEARLY 40 YEARS - from 1974 to 2012, that's probably longer than your parents have been alive!
- THE PAGES WENT IN A LOOP - like a carousel, spinning round and round. You had to wait for your page to come around!
THERE WERE GAMES TOO!
The most famous teletext game was called BAMBOOZLE! - a quiz game on ITV. You'd answer questions using the coloured buttons on your remote control (red, green, yellow, and blue - just like the buttons at the bottom of this page!).
Get it right, and you'd jump to the next question. Get it wrong... BAMBOOZLED! Kids would spend hours playing it after school.
WHAT HAPPENED TO IT?
When TVs changed from the old "analogue" signals to new "digital" ones in 2012, teletext stopped working. The invisible gaps that carried the data weren't there anymore.
TELETEXT HOMEWORK!
Fun activities to try at home:
1. INTERVIEW YOUR PARENTS
Ask them these questions and write down the answers:
- What page number did you check most often?
- How long did pages take to load?
- Did you ever play Bamboozle? What was your high score?
- What was your favourite thing about teletext?
- Do you remember the sound it made?
2. DESIGN YOUR OWN TELETEXT PAGE
We've made a printable template! Remember: teletext only had 8 colours (black, white, red, green, blue, yellow, cyan, magenta) and blocky letters.
PRINT THE TEMPLATE- Pick a page number (100-899)
- Choose a topic (your school, your favourite game, local news)
- Add a header with the page number and title
- Label the coloured buttons for navigation
- Colour it in using ONLY the 8 teletext colours!
3. TELETEXT MATHS CHALLENGE
Work these out:
- If teletext showed 25 pictures per second, how many in one minute?
- Ceefax ran from 1974 to 2012. How many years is that?
- If there were 800 pages and each took 0.3 seconds to broadcast, how long for all pages to go round once?
4. SPOT THE DIFFERENCE
Compare teletext to modern apps. Make a list: What could teletext do that apps can't? What can apps do that teletext couldn't? Which do you think is better for checking football scores quickly?
TRY QFAX!
Want to see what teletext looked like? Download QFAX and explore! Check out PAGE 316 for live football scores, just like people did in the old days.
