Nathan Dane, the mastermind behind https://NathanMediaServices.co.uk, helps us discover the inner workings and historical significance of the BBC's iconic Ceefax service. Nathan shares his journey from piecing together teletext data using a Raspberry Pi to creating a fully functional teletext website that mirrors the classic Ceefax pages. With a mix of old-school technology and modern coding, Nathan explains how he recreates the teletext experience, including up-to-date news, sports scores, TV listings, and more. Learn about the challenges of maintaining teletext formats, the intricacies of data feeds, and the community efforts to preserve teletext history.

This episode offers a fascinating glimpse into – for the UK – a bygone era brought back to life.

Behind the Scenes of Teletext: Subtitles, Data Broadcasting, and More

Former BBC engineer Peter Wietzel joins Russell Trafford-Jones in this episode of Broadcast Focus as they delve into the intricacies of Teletext covering how subtitles work, why the BBC tansmission actually used two simultaneous subtitle transitions, and the many uses of carrying arbitrary data over Teletex were were the hidden heros! Peter finishes by talking about how the implementation was one of the first cross industry examples of collaboration in creating standards and talks about MHEG which replaced Teletext. Whether you're a technical enthusiast or just curious about broadcasting history, this should be good!

00:00 Welcome & Intro

02:30 Understanding Subtitles in Teletext

04:11 Technical Details of Subtitles Transmission

10:42 Subtitle Demo

11:10 Inserting Live and Recorded Subtitles

15:57 Dealing with Lack of Subtitles & Policing

18:35 Using 'Subtitles' to Help Deal with AFD/VI/Aspect Ratio

19:34 A Second Simultaneous Subtitle System for Internal Use

21:27 Inserting Subtitles in the BBC Regions

22:50 Teletext in SDI - SDI Bridge

25:25 Second Generation SDI Bridge

27:40 Quick look at Presfax

29:06 Databroadcasting – Sending Generic Data

31:40 Uses of Databroadcaster

34:00 Dairy Farming

36:00 Carrying audio over Teletext

40:40 Presfax Details

44:36 Controling Overlay Insertion at Transmitters

46:11 Ceefax In Vision

49:25 Teletext Standards

50:58 Collaboration and Standardisation in the 90s

54:58 Technical Enhancements and Memory Management

01:02:56 The Rise of Electronic Programme Guides

01:08:19 PDC - Recording Programmes

01:20:09 The Transition to Digital Broadcasting

01:23:00 The End of Teletext and Its Legacy

01:28:00 Reflections and Closing Remarks

With thanks to https://www.nathanmediaservices.co.uk/ceefax/ for the demos and by extension ZXGuesser

Peter Weizel spent many years in the BBC working on Teletext and even wrote part of the standards so who better to continue guiding us on our journey into the first digital broadcasting on TV. Teletext is a pioneering pre-internet information distribution system. In part one, we heard about the inception of Ceefax at the BBC and the some of the inner workings of Teletext, its page and data structures, and its significant role in modern broadcasting technology. Part One: https://youtu.be/tbDB8FCOaV4

In part 2, we go into detail about data broadcasting, government interference, dynamic allocation of packets, using teletext for BBC internal staff information, regionalising CEEFAX

00:00 Welcome and Introduction

01:42 Ceefax Demo

02:11 Teletext Services and Features

03:03 Finding ways to apportion the VBI

05:11 Government Wants To Sell Teletext Space

07:15 Dynamic Allocation and Optimisation

11:18 Better Data Multiplexing

26:55 Test Equipment

31:05 Early Ceefax Architecture

33:23 Ceefax in the regions

39:49 BBC FAX service in Europe (WSTV)

45:28 Telfax – Ceefax for BBC Staff

49:04 Conclusion and Next Episode Teaser

Many thanks to Nathan Dane for bringing Teletext to the internet: https://www.nathanmediaservices.co.uk

Shout out to @ZXGuesser for the online interactive teletext viewer.

Wikipedia's summary of Ceefax: https://en.wikipedia.org/wiki/Ceefax

Wikipedia's summary of Teleteix: https://en.wikipedia.org/wiki/Teletext