The UK’s first digital terrestrial television service was launched in 1998. Offering a selection similar to analog cable and satellite but through your TV aerial. Sadly it was not long for this world, ceasing operations in 2002. However it did lay the foundations for Freeview.

Digital Channel Lineup

The ONdigital user interface with the main menu of the left and the info guide on the right

Set-Top Boxes

Pace DTR735 ONdigital
Pace ONdigital

There were five common manufacturers of ONdigital receivers, Nokia, Philips, Pace, Sony, Toshia and Pioneer.

  • Philips: One of the first to release their box, the DTX6370 had a few issues in relation to signal interference and was prone to the picture dropping out at certain intervals, later models – 6371 were much more reliable. These receivers bare a resemblance to other satellite receivers that Philips had made, such as the DirecTV receivers. Philips models feature a WIDE and Subtitles buttons on their remote to control the aspect ratio and to enable subtitles respectively
    • Was one of the first to receive the MHEG update, being rolled out in December 1999
    • The remote control and box can be switched to an alternative IR protocol if they are interfering with the TV or VCR, to do this: Power the box off at the mains, then power on but leave in standby, hold the M button the front panel for 3 seconds (-SA- will be shown on the LED display). Press the right arrow key on the box to switch to -SB-, Then press the S button to save. On the remote, hold the text and standby for 4 seconds, then type in 161, or 160 to return to system A
  • Pace: Was a common manufacturer of digital set top boxes and one of the few that made equipment for all three digital platforms (Sky for satellite, ntl and Telewest for cable) The DTR730 was the first model released in 1998, with the DTR735 released in 2000. Common difference being the 730 has a front panel flap covering the smartcard slot, whilst the 735 lacks this and has a faster processor.
  • Nokia: Only released one model, the Mediamaster 9850T. This was a popular model that featured digital audio out alongside analogue audio, it also had a front panel flap that covered the smartcard slot, CI module slot and the front panel buttons. Nokia would later rebrand the box and introduce a silver version for the Freeview market.
    • Was one of the last models to receive the MHEG update, and had a bug where using Teletext (Channel 9) could cause the box’s memory to be wiped, requiring the user to go through the channel scan again
  • Sony: Only released one model and didn’t support it for long, as it missed out on MHEG support (No interactive or subtitles) or Ondigital PPV.
  • Toshiba: Sadly this also shared the same fate as the Sony, missing out on the update that brought MHEG support
  • Pioneer: A late entrant to the ONdigital family, the boxes are silver and have a more modern appearance, similar to the Canal+ design.

ONdigital used the Media-highway middleware system for the set-top box software and interactive services. This was a full adaption of the Canal+ software that had been launched in France prior. This had also extended to the subscriber management system which was also adapted by Canal+, and was the backing system behind the MediaGuard conditional access system.

A software update in 1999 introduced MHEG5 support and the ability to download Mediahighway/Pantalk applications. This update was not automatically installed had to be started by the user manually. Once the update was installed, Mediahighway applications could be updated automatically.

The MHEG5 engine was developed by the manufacturer instead of ONdigital/Canal+ which only supplied an API path for it, This meant that different models got digital Teletext support at a later time than others, and some boxes had no MHEG support at all. Philips was the first to receive the update in late 1999, followed by Pace and Nokia in 2000. Sony and Toshiba boxes did not recieve the update, as they have ceased support for ONdigital and neglected to provide an MHEG engine.

As for Mediahighway applications, these are downloaded when the user lands on a specific channel. Typically a square shaped green coloured banner appears advising the user the software on their box is being updated. When the first major update was deployed, ONdigital customers were instructed to go to channel 50 (ONrequest) for this update to be installed), this was the update than enabled the Guide button, along with its menu options (For ONmail and ONrequest). It also seems that ONrequest and ONmail are Mediahighway applications that were downloaded to the box automatically and updated at certain times, since the ONrequest option was amended to order an event following the rebrand to ITVDigital

So from a bit of research it seems there are two ways of delivering updates to the Ondigital box:

The ‘Auto update’ method, which requires the user to access the menu and choose the auto-update option, seems to be used only for manufacturer updates, like the MHEG5 update mentioned above.

The alternative method requires the user to be on a specific channel at a certain time in order to get the update. Interestingly this was also used by Top Up Tv to deliver the SECA2 update that was required for their service to function for ONdigital box’s, since they would have been using the original SECA (MediaGuard encryption). This also means that had the box missed the updates, or was using either a Sony or Toshiba box, then they would not be compatible with Top Up TV.

MHEG and MediaHighway/Pantalk Info

Update method Information – Post 2

Sony ONdigital VTX-500U
Sony ONdigital box, a rare sighting

The MHEG support was quite buggy, A common issue with MHEG services is that the front panel stops working when the Ondigital box is switched to a channel with MHEG services. In order to regain control the STB, a remote is required to change channel to a non MHEG channel in order to restore front panel functionality. A workaround was to enable subtitles which would stop the MHEG virtual machine from functioning, as subtitles and MHEG shared the same graphics layer.

ONdigital receivers were not capable of updating their channel list automatically, as they are not reliant on the DVB Network information table. This meant that whenever new channels were launched, the customer was required to rescan in order to receive the new channels, this contrasts with modern Freeview receivers that are capable of finding and adding new channels automatically in addition to removing and replacing old and defunct channels.

The EPG on all ONdigital receivers was limited to now and next only, with no full grid-style EPG available within the set-top box. As an alternative, several EPG’s were launched as an alternative, these were provided by ntl, BBC, Teletext and Ondigial themselves as ONView. An interactive guide was also provided by ONNet. Its not known why the EPG was set up this way, since ONdigital boxes follow the same memory specifications as a typical Sky digibox have, and was a huge disadvantage compared to Sky and cable platforms which had their own TV guide embedded into the STB firmware.

Pace DTR735
PhilipsDTX6370Physical On/OFF switch, Wide and subtitles buttons on remote
Nokia9850TDigital Audio output (S/PDIF)
SonyVTX500UOptical Audio output (S/PDIF), No MHEG support
ToshibaDTB2000No MHEG support
PhilipsDTX6371Physical On/OFF switch, Wide and subtitles buttons on remote
PaceDTR735Faster processor
PhilipsDTX6372Physical On/OFF switch, Wide and subtitles buttons on remote
All Ondigital receivers follow the same specification and software although some models may differ in features depending on software upgrades provided

Full ONDigital STB Lineup


An email service designed to be used with ONdigital. Although the ONMail software is capable of running from the set-top box itself, an additional hybrid remote/keyboard and receiver accessory was needed in order to use the service. The receiver uses the internal STB modem to connect to the services, and messages are downloaded to the ONMail receiver unit, which the ONdigital receiver communicate with. The receiver unit was connected to the RS223 serial socket on the Ondigital receiver and was accessed by pressing the Guide button and choosing the ONMail option. An account with ONMail was required, email accounts from other clients was not supported.

Nokia OnDigital
ONMail interface


An internet add-on service that was similar to the Bush Internet TV and Microsoft WebTV in concept, where a keyboard and STB are provided and are used to access the internet via a dial-up connection. Ethernet was not supported which meant broadband connections could not be used. Unlike ONmail, ONnet was not reliant on the ONdigital set top box, instead the ONnet box simply passed the ONdigital SCART signal through a quarter screen interference, allowing TV to be watched whilst browsing the internet.

Pioneer ONdigital ONnet
Pioneer box with ONnet


ONdigital had one of the first integrated digital televisions, where a DVB-T receiver was embedded into the TV itself. There were two different forms of IDTV, the most common was that the TV manufacturer would install a DVB-T tuner inside the TV, with the TV itself running on the manufactures own firmware, and may not integrate a conditional access system or middleware due to licensing costs. In order for these TV’s to be used for ONdigital, a CAM (conditional access module) would need to be provided by ONdigital. With this, the customer would insert their ONdigital smart card into the CAM itself, and would then insert it into the TV. This would provide the TV with the capability to decode ONdigital broadcasts. This would not however allow the TV to load Mediahighway interactive services unless the TV itself supports it. Only MHEG applications would load such as BBC Text, later BBCi.

The other type of IDTV had an actual ONdigital set-top box chipset installed into the TV, this was similar to the LG Sky IDTV where the exact ONdigital user interface was provided, allowing the customer to insert their smartcard without the need for a CAM, and had access to all interactive services.

IDTV Manufacturers with ONdigital integrated (No CAM required)

  • Bush
  • Matsui
  • Philips

PVR’s may have been in development prior to Ondigital’s administration. It is probable that the Pace Twin PVR was originally designed for use with ONdigital since it featured a smartcard slot and came out in late 2002. The Pace twin PVR was based on the technology they had acquired from XSAT in 2001.

Free To View

Even though they were designed for use with ONdigital, the boxes were completely functional without a subscription, and some were purchased for the purpose of FTA viewing. Even without a subscription, you were able to receive the BBC suite of digital channels, such as BBC Choice, Knowledge, News 24 and later CBBC and CBeebies. These channels were receivable on IDTV’s also.


Even after ONdigital had entered administration, the Ondigital boxes remained functional and were pivotal in the launch of Freeview as it provided Freeview with an existing install base to encourage channels to launch on, and were also used for TopUpTv, a successor pay-TV platform focused on entertainment channels. However by 2004 they were beginning to show their age with their lack of support for a 7 day EPG, speed of channel changing and digital text due to the slower CPU’s and glitches within the MHEG virtual machine. Despite their age, they were still functional long after Freeview had implemented the split NIT (Network Information Table) change, where the NIT was split across multiple frequencies due to the growth of digital channels, some earlier Freeview boxes (typically set-pal based models) were not capable of handling the changes to the NIT. This was controversial as the ability to handle a split NIT was one of the key specifications of the DVB-T and D-book specifications, and there were arguments as to why these boxes had the Digital ‘tick’ certification, and if these products were fit for purpose since they were obsolete only after 3 years of use or some models. ONdigital boxes however were invulnerable to the split NIT change and had continued to operate.

8k Doomsday

The final nail of the coffin was the digital switchover, where the analogue signal was switched off, and the DVB terrestrial signals were switched over to 8k transmission from the existing 2k modulation. By that point Top UP TV had already dropped support for ONDigital and had migrated to newer encryption standard, along with a new PVR.

ONdigital was one of the first digital terrestrial platforms in Europe, and was the first broadcaster of DVB-T in the world. In order to launch the service early, ONdigital elected to use early Motorola DVB-T chipset demodulators. This would have enabled them to launch on time in 1998, but they would have been regulated to the 2k standard rather than the 8k used today. 8K chipsets became common in 1999 but at that point 2K only chipsets was available cheap and Ondigital continued to use them to reduce the costs, since the STB were being loaded out.

Freeview had continued to broadcast in 2k up until the digital switch over. This change had also affected IDTV of the same time period, and some launched Freeview boxes also (Pace DVTA). Ironic considering these boxes would have been brought to prepared for the digital switchover, only for them to become obsolete also.

Documents & Manuals

More Information