ntl launched it’s digital TV service in 2000, shortly before acquiring the Cable & Wireless consumer division. Since the two networks had select differences between the implementation, it took some time before the networks were fully merged. The original network is referred to as ‘Langely’ as that was the location of the main headend and playout centre.
Now & Next
Now and next banner that appear when you change channels
You can bring up the information banner, which shows what’s on now and next, and allows you to browse through the channels on ntl digital
TV Guide Listings
Pressing Guide bring up this menu, this gives two options. The regular channel guide and the On Demand (NVOD) guide
The guide layout is quite different here compared to the grid view that other systems like Sky Digital use. Here you select a channel from a list which will then show a page full of listings.
Pressing info brings up a description of the program or episode
TV On Demand
Front row was the services used to provide PPV events for cable customers, similar to Sky Box Office
A list of movies and events to order
Purchasing a movie,
Appears when the set top box is in the process of starting up
A revised update now adds a reminder diary feature, that allows reminders to be set for future program’s – similar to the Sky personal planner
The Di4001NC was a cost reduced cut down version of the Di4001 series of ntl set top boxes. One of the noticeable differences is the removal of the second card slot, in favour of just a single smartcard slot for the smartcard. The second card slot was originally designed for Mondex cashcards, which never launched.
Another removal was the ethernet port, despite the box still having a built in cable modem, the IEEE1284 port has also been removed, along with the audio output
From left to right:
RF Out – outputs the RF modulator, does not pass through the cable signal
TV & VCR Scart
IR Input & IR Output – No official function
RS232 – No official function
The RF output no longer includes an internal combiner, which means you will no longer be able to tune in cable channel’s via the RF tuner. Instead only the modulated output of the set top box will remain. This was due to the intention of removing the analogue channels, and to prevent the DVB-C channels from being tuned in on modern digital TV sets.
Well it looks very similar to the Di4001, but on closer inspection you can see the components removed, also in this model there aren’t any stickers covering the various chips.
The removal of the ethernet and IEEE1284 controllers, the ethernet port seems to remain but is not wired internally.
A closer look at the Broadcom DAVIC processor and the mysterious Pace chip, of which the sticker covered some of it on the previous model. At the very top you can see the main processor, which is unchanged since the previous model (Hitachi SH3)
Hitachi SH-3 HD6417709
Pace 909 6162800, ORBIT 61628
Broadcom QAMLink BCM3120KTB
To access, hold the Up/Down buttons upon bootup, and release when DIAG appears on the front panel display.
Default frequency settings, this would carry any software updates the STB would download upon boot up
Some version numbers, as well as the Network ID. This box appears to be running CR3.2
Further information in relation to the software versions on the STB
Since this revision lacks the internal combiner, you cannot control the outputted cable feed
Service status of the box, indicated that the signal is OK and the regional information
Signal information for the current frequency, this is the same frequency as the default frequency
Information relating to the DVB-SI, and the amount of services received
CAT – Encryption systems
PAT – Channel numbers
TDT – Updates the time & date
EIT – Event info, current program
Information for the inserted smartcard, the credit amount and the pairing status
A log of events generated by the STB
Signal strength status, but this time for the DAVIC tuner (also known as DVB_RC)
Same as above but for the upstream
Browser settings, for the Liberate navigator client
Current date and time, this cannot be set, but is retrieved from the network stream, the STB has a built in CMOS battery
Bootloader version and flash information
Memory information, according to these values the box has 16Mb, with 4Mb Flash
Information relegating to the MPEG decoders. You can also set the remote control configuration here and enabled the rear in or outputs, this has little effect since the software does not support this
No PPV events…
Flash memory information, the capacity, bad flash sectors and where the image came from.
When Cable & Wireless launched their digital cable service, Interactive TV was the main attraction and focus for the platform.
Cable & Wireless teamed up with Liberate to deploy it’s eNavigator middleware client for their set top boxes. Liberate had already made deals with many US digital platforms for both Motorola and Scientific Atlanta networks, and had partnered with Acer & Thomson/RCA for their own set top box / internet tv devices. These allowed for the internet to be browsed on a TV itself, similar to a webTV or the Bush Internet TV. With that in mind it made sense to go with Liberate for its interactive platform, with many of the interactive being HTML based, essentially being microsites being designed to be useable on a PAL TV screen, as well as being usable on the set top box hardware itself. By using a HTML based system, it would be easy for existing web developers to adapt their websites for cable interactive TV.
The main interactive developer portal, viewed within the Cable & Wireless interactive browser. This also showcases the browser interface, note the lack of address or URL bar, since this service was designed to be a walled garden. Instead a url bar is provided on the developer portal, likely to allow developers to test their websites.
An interesting oversight is if you sent an email with a hyperlink embedded into it to a website such as Lycos or Google, you could use that link to open the browser to that page, and if its a search engine you could use that to load other websites that are not part of the service
Not much to say here, the developer portal provide links to documentation details the requirements and limitations of the TV internet platform. This goes into details the specifics of the Liberate eNavigatior platform.
Viewed in Internet Explorer 5
A look at the services…
Unfortunately the screenshots are of a low quality and resolution since they have been extracted from the PDF documents above but give a general idea of the scope of the service provided. Some screens have the browser banner at the top of the screen, I’m assuming these are portals to the microsites.
Another view of the interactive home screen, this may be from a later redesign
TV Internet Home
Similar to the Open… home screen, provides links to various services available
Sports Main Menu
Provides links to other sports themed websites,
Email Main Menu
Menu options are Check Email, Write Message, not sure of the third items, Drafts? Templates? Deleted?
The STB had a built in email client, designed for the C&W email service
Two Way TV
Looks like a games service, hard to tell because of the resolution
A resource for traffic information and a route planner
Looks like some sort of holiday broker
Provide links to holidays, not sure if this goes directly to the sites themselves?
News headlines, and weather from various sources.
When the consumer division of Cable & Wireless was acquired by ntl in 2000, the interactive platform continued it’s development. In 2002 ntl deployed the Liberate 1.2 middleware which bought improvements to the browser rendering engine, and the TV guide was rewritten to take advantage. ntl would later spend time developing services for the Langely platform, which was originally planned to use the PowerTV platform, but chose Liberate instead. This was done to ensure parity between the two platforms.
Connecting an old ntl box running ancient (by cable standards) software to a modern Virgin Media network. Whilst Virgin Media is the sucessor to ntl there are a few possible roadblocks to this;
VM no longer broadcast their channels in MPEG2 with the exception of a few off air slates and radio channels.
The DVB-SI that VM broadcast may not be consistent with what the software is expecting
The STB itself may be looking for something that VM are no longer transmitting
Getting the box to boot was a struggle itself, just connecting it to a cable feed is not enough since the box will get stuck on the starting up screen, I left it overnight and the box was still trying to start up
Forcing a boot (holding Up+Down and letting go once LDR appears on the display) wouldn’t work either
What worked in the end was to power up the STB will the cable feed disconnected, this will cause the box to display NIT on the front panel LED display. Connecting the coax feed, the box will then proceed to the start up screen and after around 5 minutes a channel will be displayed.
Well the box managed to load something, lets see what we get…
The main EPG, showing the many channels or streams Virgin broadcast
What’s disappointing is nothing can be tuned, you can select a channel but nothing will play, not even radio channels. Potentially this could be the NetID mismatch causing this , since the STB originated from a different area of the network.
Looks like software update streams for the various tivo box models currently in use with Virgin Media.
To breakdown what works and not
Channels Numbers exist but its not the order that Virgin use, the STB seems to place them consecutively in the EPG, i.e starts at 1 and goes up to 350
There are issues selecting channels over 255 in the guide, trying to select a channel number over 255 causes the box to pull a channel from the top section of the EPG, i.e selecting channel 260 causes channel 5 to get selected instead.
Only now and next information is loaded, no further schedule information is available
Subject search does not function
Channel genres do not work, selecting Entertainment or Sports shows no channels.
Various hidden streams and channels appear in the guide
Changing channels using the + and -, the list is out of order and the STB seems to jump between different channels.
Program reminders work and can be set
Maybe changing the Net ID will at least allow the radio channels to be opened
Earlier I went though the ntl CR3 Bromley software which was introduced in 2002 and was the basis for ntls new interactive services.
The Pace Di4000 was a redesign of the previous 4001 and 1000/2000 series box. Its worth mentioning that Pace’s model numbers don’t seem to follow a specific scheme, you would assume the Di4001 was the successor to the Di4000, however the Di4001 was the launch box for ntl in Langely areas and was a DAVIC based box, with the Di1000/DiTV1000 being its DOCSIS equivalent for Telewest and ntl Bromley areas.
These early generation boxes were designed around the Hitachi SH3 CPU with C-Cube Chipset for MPEG2 decoding and descrambling. The Di4000 replaces that with the Broadcom demodulator and the Conexant MPEG2 decoder which contains the ARM CPU.
Left Pace Di4001, Right Pace 2500 Sky Digibox
The main difference you will notice between the two is the reduction of components, with the Di4000 only having two main processors. The previous generation was split over 5 different processors. this reduction means the mainboard is smaller and the box produces less head as a result. In fact its not too far off an average Sky Digibox.
The Power supply is now separated from the main board, like the Sky Digibox design, allowing for the PSU to be replaced independently from the main board.
The audio out jacks have been removed, no you can no longer connect the box to a Hi-Fi system unless you use a scart breakout adaptor. The design for it still exists on the main board however.
The Serial port and Printer part are removed in favor of a single USB port. the serial port still exists and can be access using a VCR to RS232 adapter.
The second card slot has been removed, this was originally designed for Mondex cashcards.
The remote control protocol now supports IRDA and RC5
Conexant CX22490 – ARM920 based core, 160Mhz – 175MIPS
Broadcom BCM3250KPB – Demodulator
CrystalLAN CS8900A-CQ – Ethernet controller
Conexant Bt861KRF – Video encoder for Scart/AV output
The tuner modules, one for TV and the other for data/DOCSIS modem
Ethernet – For internet connectivity for the internal cable modem
USB port – To connect additional devices, never used officially by ntl or Telewest
IR in/Out – never used by ntl or Telewest
To access these on this box, hold down the Up & Down buttons whilst the STB is booting, and continue to hold them down until you see this screen. The front panel LED display will change to ldr and will then go blank once you have entered diag mode.
Sets the default frequency which is checked when the stb boots up, this frequency carries the netid for the area and any software updates
Shows build information about the software loaded, and the hardware identifier of the box.
The replacement to CR2 software that saw the launch of interactive services for the bromley platform, CR3 saw a rewrite of the guide software, with everything now being written in the Liberate browser, and Two Way TV support for downloadable applications, whilst Liberate being used for interactive. This software would form the basis for Langely CR3, and would be the next step in unifying the platforms in terms of feature set.
Sadly not all areas had access to CR3 with former Videotron areas in London being stuck on pre-interactive CR1 blue to the networks inability to support a return path connection. ntl would have to upgrade and repull the network in order to provide support for broadband and on demand services, all of which are dependent on a return path.
The software here is running on a Pace Di4000N
The user interface of ntl digital, not a fan of their purple/pink colour scheme and the bad thing is that its everywhere, thankfully they changed the scheme by the time it can to Langely.
Interesting is the listing for interactive settings, rather than be part of the list it looks like a separate link,
Now & next
Unfortunately the purple makes it’s way onto normal viewing, with the now and next bar
I’m not sure why these early cable TV software did not allow for the volume to be changed via the STB remote, since the Telewest side also did not support changing the volume. One theory was that customer would complain to ntl about how they were unable to her any sound through their TV, unaware that the volume on the analogue box has been set to a low level or mute, so to prevent further calls that disabled the feature.
In the end they enabled the volume control in a later build ofCR3, along with Telewest. Maybe they got fed up of the support calls asking why the volume control isn’t working on their box. In hindsight they should have followed the Sky design where the STB remote controls the volume on the TV at launch (they ended up doing this later, with the newer remotes)
The options button gives a small menu, allowing for access to the help function and a shortcut to the diary. The audio Language lets to changed the language of the audio, or enabled narrative audio description, Sky would later implement a similar feature in its Sky Guide.
The main TV guide grid. No channels here since the box is not connected to the cable feed.
Here would have been a list of all channel genres, such as Movies, Sports, News, etc
Pressing the i button shows a short description of the program
TV Guide: Diary
The diary is ntl’s version of the personal planner, and is used to store reminders for future events and shows. Future PPV events appear here.
The subject search feature can be thought of as an alternative to the A-Z listings of Sky Guide, showing programs rather than the channels themselves. The idea is that the customer can find a program they like by the genre of the show.
Sadly the TV guide only has 3 days of TV listings, compared to the 7 days offered by Sky Digital.
A list of subgenres
Searching for a specific program via text
The on screen keyboard, not sure if this is the way it’s supposed to look since a lot of the text to the right being cropped off.
ntl customers could also purchase an optional keyboard to make it easier to enter text.
One nice feature is the ability to save personalized genre lists, here you choose the type of programs to like to see and you can easily search for that list without having to manually select categories.
Trying to load interactive services which sadly no longer exist. the Liberate middleware was used to deploy the interactive microsites, with the TwoWayTV middleware being used for the interactive applications such as games.
Looking for PPV events, this was before true video on demand had launched
The parental control feature
Changing TV settings, not sure what Enhanced Programming corresponds to?
The favorites feature, very similar to Ntl Langely CR3
There’s a help system but with no content stored on the box.
Diag screen that shows the software an signal information
Using with Virgin Media
Somehow I was able to get the box to bootup on a modern Virgin media connection, with many Channel and TV listings being loaded. Sadly I was not able to get any TV channels to load, not even radio channels which still broadcast in MPEG2
Former Telewest/Virgin Media box used for standard definition TV Services.
Sadly the NetID for this box does not match my area, which means channels cannot be watched. Virgin have migrated their streams to MPEG4 anyway which this box cannot decode, however radio channels remain in MPEG2 although they are tied to the NetID which is why they don’t appear here.
The now and next banner that appears when you change channels. If you are used to Sky’s interface you will be familiar to how Virgin’s guide works since it’s mostly the same principles. Left and Right lets you browse the different channels, which unlike Sky will automatically filer out unsubscribed channels, and you can view information for all channels for the next 24 hours
When you remove the smartcard from the set top box
The main home screen, typically the channel you are watching appears in the box to the right. You can’t do that on a regular Sky Digibox. From here you can also access the on demand and catch services, which at the time would have consisted of BBC iPlayer and content from ITV and Channel 4. For a brief period Virgin also offered box-sets in the form of Virgin Central which could be accessed like a regular channel
Channels can be divided into multiple genres. Oddly there’s a high definition section there, despite the box lacking the ability to decode HD channels.
The main TV guide screen
Setting a reminder, similar to adding a programme to the personal planner on Sky
The favorites guide, channels you mark as favorite appear here
The reminders section, similar to the personal planner on Sky Digital
Sorting channels by genre
Box supports RGB and composite over scart, and has a widescreen option. The EPG does not run in widescreen mode however.
OnDemand and Interactive
Press F to pay Respect… or OK. I guess most of the liberate interactive stuff has been removed
For years Telewest customers were promised the launch of digital text services that could be activated by the text button. Eventually they just gave up
Pressing the Help button brings up a short guide that mentions most of the common features
Kind of like the BIOS of a PC where you can change certain settings like the default frequency. To access it hold down the Up and Down buttons on the front panel of the box whilst it is booting up (whilst -un- appears on the front display). DIAG will then appear on the front
The only thing you can change here is the default frequency parameters. and the RF output.
Inside the box
I’m not sure how similar our 4200DVB is to the American version of the 4200. I guess the CPU chip set might be the same but the software will defiantly be different, since Scientific Atlanta have their own Operating System and middle-ware stack, whereas Virgin use Liberate TV Navigator for their software. Then there’s the DOCSIS modem compared to the DAVIC based one in the American version, and the different encryption systems (Nagravision vs PowerKey)
The internals are similar to the Di4000. One thing I have noticed with Scientific Atlanta boxes is they always mount the PSU on the side. I’m not sure if this allows for better heat dissipation since there are vents underneath the box. The tuner module is huge and takes up a lot of room on the main board.
The CPU (right) with the cable modem coprocessor (left). The CPU seems to be a customized chip for Scientific Atlanta and is designed by ST. This may indicate the CPU core being ST20 based, since many ST chips used that core in various satellite receivers, including Sky Digibox’s. As with modern designs, the main processors integrates the CPU, MPEG2 decoder, CA descrambler and graphics core on the same chip. In terms of memory, the box has 32MB of RAM and 8MB of flash, same as the Pace Di4000T.
The IO is standard for many cable boxes of the era, although this model drops the USB port, and the RF loop through has been removed. The earlier Pace Telewest boxes had an RF loop through that would modulate the STB signal onto a spare RF channel, whilst this box does the same, you cant loop the antenna feed through it, wither a combiner or diplexer device would be needed. Assuming you even wanted to use RF, most customers would use the scart connecter with the RF being used to feed a second TV. I’m not sure if the box feeds the analogue cable channels though the RF out, but since this box was released in 2004 and Telewest were already planning to shut of the analogue feed it’s unlikely.
At least there’s an Optical audio out along with analogue out, which the Di4000 boxes dropped, and the mysterious IR blaster connector.
Front view of the STB, the panel is based on the Scientific Atlanta 4250 design.
Updating System Software
To force a software update, power off the box, hold Power and Ok whilst powering the box on
It’s nice they used Wordart in their software update screens
A look at ntl’s CR3 software for the Langely Platform
CR3 was ntl’s long awaited upgrade for their Langely customers who had previously no access to any interactive services, unlike the Bromley division that had full interactivity for some time. Part of this was due to the different return path technology used, ntl had originally went with DAVIC compared to Telewest and Cable & Wireless who deployed the DOCSIS standard for their TV return path. Although they are similar in terms of functionality, the differences meant ntl could not adapt the Cable & Wireless software for the Langely platform. In addition, Langely areas also ran different software with the original EPG being provided by Pace with the Liberate 1.2 browser being installed. CR3 would see a rewrite of the entire guide with everything now being done in Liberate, this meant that the Liberate browser was loaded on start-up, unlike earlier versions where the user had to wait for the browser to load.
CR3 saw a drastic change in the user interface, with the new ntl colour scheme being adopted
Screenshots below shows the stb without nay channels loaded, I have to force boot the stb by holding they down key until Boot came up on the front panel display. Sadly I was unable to get the box to load with the cable feed.
Now & Next
The main user interface layout, you can see the Sky Guide influence with its layout
Viewing all channels, this would be populated with all subscribed channels, unfortunately the STB does not pick up any channels, either it cant load the NIT or the tuner inside the box is knackered
Viewing channels based on genre, up to 7 channels can be displayed at any time
Diary function, this is like the Personal Planner on Sky Guide, you can schedule future programmes to be entered here. Unable to test further since the box can’t load any programmes
Ntl revamped replace its PPV service with a full on demand service, the programmes ordered could be watched easily. This software seems to be from before on demand was implemented as despite the menu saying ‘On Demand’ the box shows PPV options instead.
Not functional 😦
ntl had the ability for the customer to rearrange the channels in their EPG, allowing for channels to have their own number. This feature was removed when they migrated over to the Telewest based UK1 software
I can soft of understand why the feature was cut, in a family household one could easily rearrange the channel numbers which would cause issues with other members trying to figure out the channel numbers, and probably resulted in increased support calls from customers trying to figure out what had happened to their channel list.
Changing the picture settings
Never seen this before with digital TV, the ability for the box to sound an alert, with Sky boxes you can only sound a beep, and that’s only if there’s an error or if there are subtitles on programme being watched. Three alert sounds are available. Sadly this feature was cut when they migrated to the Virgin UK1 software.
Favourite channels can be viewed in a list form the channel banner
Listings for favourite channels can also be viewed whilst watching a channel.
I wanted to see if this box themself would still work on a modern Virgin media network. I’m aware that Virgin broadcast all their channels in MPEG4 which this box cannot decode, aside from some radio channels. But I was still interested if the box would work and how it worked, especially in regards to early digital cable TV.
The box itself
Pace Di4001 size comparison with the Pace 2500S5, a typical Sky box of the same era
Trying to get started
So I got off to a rocky start trying to get the box to start up in the first place, since powering it on the display would show PACE followed by TUNE. I figured that i needed to enter the boxes engineering mode to reset something. This provided impossibale since after attempting to enter the engineer mode, the box would immediately show TUNE on the front panel display
i tried different combinations that I found online to get the box to work but nothing was working. Finally i stumbled on a old forum post that held the solution;
So to summarize, If your set top box wont progress past TUNE (shown on the front panel display) and you are unable to enter into the boxes engineering mode, you may need to reset the STB’s NVRAM since it may have become corrupted. This can occur when the STB has been powered off for a while, and the battery has discharged to a point where it is running under voltage. This must corrupt the NVRAM in a way it becomes unreadable to the STB
To recover, you will need to open the box, and pull a red jumper located to the right of a large white Sanyo battery. Leave the jumper out for about 5 minutes and then reconnect the jumper. Power on the STB and hold down the UP and DOWN buttons on the front of the box for 10 seconds. You should see DIAG on the front panel display and the engineering mode should appear after a few seconds.
Doing this will clear the Netid of the box, which the Di4001 boxes are able to set automatically if they are in an original NTL area. Otherwise it will appear as *****
After resetting the NVRAM I was able to get to box to enter it’s engineering screen.
From here you can change the default frequency and symbol rate, which the box uses to look for the latest software, and possible where the ntl EPG listings are located. You can also see info relating to the software version running on the box, Memory and flash info
There are a few interesting items here, mainly the memory address section. from here i was able to find out the spec of the box. 0x1000000 converts to 16777216 which I would say is 16Mb of RAM. The Flash storage being 0x00400000 that converts to 4194304 which i’d say is 4Mb.
This model of box does have less Flash compared to the older revisions of the Di4001 in favor of more RAM, maybe the OS is compressed into Flash, which is then extracted upon boot into RAM, and runs from RAM like a Ramdisk. Alternatively, there may be a basic guide stored in flash, with the remaining components loaded from ntl either directly broadcast or using it’s DAVIC modem.
Also it appears this box is the 2A revision of the Di4001. which the boot-loader being compiled in September 2000
If you want to boot the STB without a cable feed connected, hold down the up OR down button on the front of the STB when PACE appears on the display (immediately after applying power to the box), and release until it shows boot, or after 10 seconds. This will skip the default frequency checks and will load the main TV guide interface, even without a cable feed connected.
Doing this trick allowed be to bypass the default frequency check and put the box into some sort of ‘safe mode’, this it it would load the TV guide without having any channels or listings loaded. In this mode the box is stuck on channel 0 and not all aspects of the guide can be accessed.
I’ll put up some screenshots of the guide software up later, if I can get the box to pick up Virgin’s tv guide…
One oddity was the services button on the front panel of the box, now you would think that it would take you to the main TV guide, however it just make the mini guide appear and disappear from the front panel there is no way to access the main TV guide screen…
Another oddity was that pressing the front panel buttons would cause the remote light to indicate, even though you were pressing the front panel buttons and not the remote.
Unfortunately I was unable to get the box to tune into any frequency, never-mind booting with some sort of TV guide. At first I assumed it was because the network information Virgin Media broadcast in my area was not in a compatible format, or that the box was looking for something that Virgin have since removed from the stream, however I am now convinced that the tuner in the box is most likely faulty, since entering correct frequency’s in the engineer screen yields no change to the signal levels, even after removing and reapplying the coax cable.
Also since the box is running relatively old software (from around 2005), it’s likely the box was an ex-subscription box that was never returned to ntl, or may have had it’s flash chips modified to be read only, preventing a software update from taking place.
Lifting the lid
Compared to other set top boxes of the era this ones quite busy inside considering it’s supposed to house a digital cable receiver and a cable modem in one enclosure. Ill try my beast to break down the individual processors this box contains;
The main decoding processors, the one on the left (C-Cube 600L) is the MPEG2 decoder, not sure of the one on the right?
The one on the left is an Hitachi SH3 processor, if you’ve ever opened a Sega Saturn or a Dreamcast you should be familiar with the Hitachi CPU’s. The one on the right is a mystery, its branded as Pace but I cannot find and information online regarding it. I suspect its something to do with Nagravision based on the fact its near the smart card area. Maybe Pace had to licence their own Nagravision descrambler?
C-Cube Avia-inx – Handles DVB-C demuxing from the tuners, Ethernet controller, IEEE1284 controller and has a built in graphics processor. Basically like the northbridge/chipset on a pc.
The system memory, unlike other STB’s of the era this one is designed to be upgradable but seems to be using a proprietary slot. Virgin Media could easily upgrade the memory of these units should the box be returned. This model currently has 16Mb.
DAVIC/DVB-RC decoder, was underneath the smartcard slot so I had to get a funny angle
I believe these are for the onboard ethernet and serial ports
The front panel exposed, note the two IrDA sensors
From Left – Right
Audio phono out
TV and VCR Scart
IR output and input – I think were were meant for external devices such as Tivo or VCR’s to control the STB without any dongles needed, whilst never used by ntl the box does supply power though these connectors allowing the use of red eye dongle
Ethernet – For internet access or LAN
RS232 – Only used for libdebug, never used by ntl externally. Could be used for external input devices like a mouse or keyboard
IEEE1284 parallel port – never used, might be for external disk drives, printers or modems