Sky Digital launched in October 1998 and was the first digital service in the United Kingdom.
Both the remote and Sky guide interface were the product of extensive usability testing. And were designed on the principle that the user should only be three button press away from the function they want access to. If an operation took longer, it was though the customer would get frustrated or see the feature as being inconvenient to use.
This is demonstrated with the sky guide interface, each portion of Sky is sectioned into four main sections, Tv guide, box office, service and interactive, which are reflected on the remote itself and are disguised to stand out from the other buttons,
If a user wants to access their tv guide listing their path follows:
TV Guide > SELECT > Digibox display all tv channels
If a customer wants channels of a certain genre
TV GUIDE > 3 > SELECT > digibox shows only movie channels
Customer wants to see all movie on boxoffice
BOX OFFICE > 2 > Digibox shows movie box office events
The layout, font size and design were dictated for the limitations of the CRT televisions of the time and to allow the text to be readable on screen despite the low resolution of the TV’s. The bottom of the Sky guide screens tell the customer what they can do next, they can either filter or shortcut to anther feature using the colour buttons, or they can press Select or backup to choose where to navigate text. If a customer wants to see more information, they can press the I or help buttons. I typically gives information on the selected item or programme, whilst help gives basic navigation and interaction instructions.
The Sky button
Arguably the most important button on the remote, allows the user to return directly back to TV. If a customer gets stuck within a menu or an interactive service, or wants to quickly escape and return to TV without having to repeatability press backup, the Sky button simply acts as the Esc key on a computer keyboard.
The Sky button is placed at the top of the remote so it is one of the first things the customer sees on the remote and the most memorable since it stands out from the other buttons with its logo typeface and blue background. The positioning from other keys helps prevent accidental keypresses.
The Sky button also brings the digibox out of standby, and if the tv connected via SCART will automatically switch over to the AV SCART input. In many ways it acts as the power button.
All Sky digibox’s employ the same characteristics, the only major difference being the speed of the processor inside the Digibox, All of them feature;
This was originally designed for cash card slots and was designed to be used with the upcoming Mondex cashcard, are precursor to the modern chip and pin system we use today. Since the digibox was designed for interactive services, and that home banking was one of the characteristics of interactive TV, it was to allow the customer to insert their cash or bank card in order to pay for goods and services.
This was never utilized during the first few years of Sky, which would have been the best time to utilize this. However Sky later launched, and closed a Sky credit card services where purchasing goods with the Sky card would reduce your Sky subscription payment, for example spending £10 on your Sky credit card would knock off 10p off your monthly Sky subscription bill. The customer would hen insert the card into their digibox in order too check their balance on the interactive service. This was the only function of the card as the customer could not make any purchase through Sky Active, and many retailers had pulled out at this point.
This was an amber colour light that was included on all Digibox’s up until the 2010 Sky+HD boxes. Initially it was through to be used for the Open/Tak21 email services, and would light up if a customer was to receive an email however the Digibox lacked push email functionality. The actual purpose was for Sky to send broadcast message alerts to their Digibox’s via the satellite signal. These messages could be for informing the customers of upcoming PPV events, newly launched channels, upcoming offers and potentially alerts specifically tailored to the customer such as a package upgrade. A software update in 2004 added a Message alert function which could be activated by pressing the yellow button on the remote control, however it was still unused as pressing the button simply yielded a ‘ There are no message alerts’ notification.
At the back of every digibox produced up until 2006 was a backplate with the worth’s General Interface, which when unscrewed contained PCMCIA slot which was to allow future plug in modules to be inserted. This was thought to be a means to expand and future proof the digibox by allowing the user to install new hardware. Sadly it was never used by Sky officially and was taken out of the digibox specifications around the same time SkyHD had launched.
Possible uses were:
- DVB-T tuner – this was rumoured to be in the works shortly after Sky digibal had launched, as Sky originally did not carry ITV due to bandwidth limitations needed to carry the different regions for ITV. This would have allowed the digibox to receive local terrestrial programmes such as BBC, ITV, Ch4 and 5.
- Optical Out – this could have ben used to provide an S/PDIF or TOSLINK connector to the digibox, allowing it to output sound digitally to an AV receiver or a stereo amplifier, since the digibox lacked Dolby AC3 support, the digibox could have outputted this externally to a received for it to be decoded. Sky+ would later launch with an Optical output instead, along with the Sony VTX750 digibox
- Ethernet – Could have added access to on demand services and would have allowed sky to compete with the on demand services launched by ntl and telewest in ate 2005, some Sky boxes did include an Ethernet socket such as the Thomson Sky HD digibox. Sky’s on demand service however rely’s on the customer downloading the programme directly to the hard drive, as unlike ntl and telewest which use their own network for transmitting on demand ontetn, Sky have to rely on BT ADSL infrastructure, and some customers make not have enough bandwidth to stream content live. which would not have been possible on a regular digibox unless external storage was provided.
- MPEG4 AVC decoder – allows the digibox to receive MPEG4 SD channels, this would have worked by converting the incoming MPEG4 stream to MPEG2 where it could be decoded by the digibox, allowing Sky to transmit their channels in MPEG4. They would still only transmit in SD resolution.
- Conditional Access – Probably the intended purpose. As Sky had used Videocrypt for their analogue transmissions prior to their digital launch which was notorious for being compromised, and that the Directv implementation of Videoguard had already been compromised also. This would have allowed Sky to incorporate a new form of conditional access should Videoguard itself become insecure.
- Additional storage – This would have been useful when Sky had to stop launching new channels due to memory limitations, a memory upgrade in the form of flash memory which could have been used to store TV listings for the search and scan banner rather than storing this in the digiboxes RAM. This cannot be used to expand the RAM directly as the interface is too slow for that, rather using it as a paging file similar to how Virtual Memory functions on PC’s
|Open…||1999||2001||Relaunched as Sky Active|
|Playjam||2000||2010||Interactive gaming service|
|YO-YO||2002||Mobile based chat service|
|Sky Customer||2001||Support for Sky customers, formally Sky Enquiries|
|Sky Gamestar||2002||Relaunched as Sky games|
|Yoo Play TV||2003||2005||Formerly GoPlayTV|
|NHS||Portal for NHS web services|
|Sky Active||2001||2011||Replacement for Open… proided access to different interactive channels|
|TV Links/Sites||2005||2007||Allowed websites to launch waptv sites for the digibox|
|DirectGov Info||2004||2007||Similar to NHS, provided information for goverment sites|
Pace were one of the leading manufactures of digibox’s, and were one of the first to launch their Digibox, the 2200 in October 1998. As Pace were a common supplier of analogue videocrypt decoders for Sky. The 2200 was the first digibox released by Pace, and there are several different revisions of this model. The 9F01 version incorporated a ST20-TP2 processor running at 40mhz, and used a separate MPEG2 decoder and a Fujitsu Videoguard decoder processor. These early models have the ‘egg’ logo branding on them. A second revision, the 9F02 upgraded the processor to a ST20-TP3, which saw the main CPU and videoguard descrambler combined into one package, and the clock speed increased to 50Mhz. These models typically have the ‘Swoosh’ logo style on them, but some units still have the egg logo. Like all early model digibox’s the ST20 processor was used as this was already used by Directv in the US for their set top units.
Pace would continue to release further digibox’s based on the 2200 design, and introduced the 2300 and 2400 respectively. The 2400 was a slight redesign of the front panel of the 2200, however the internals remained the same as the later revision 2200. The 2300 was the same as the 2400 but in silver, and rumoured to be exclusive to comet. These models were released in 1999, and all had the identifier 9F02, with the 9F03 releasing later. Because these models have a different front panel design, but share the same internals, it makes sense to identify them by their identifier, rather than the model number.
Around this time, Pace also partnered with LG to produce an ISDTV, which was a TV with an integrated digibox (different from the later Panasonic IDTV, which had an integrated satellite tuner) and have announced a partner programme, where they would produce digibox designs for third party companies, one example was Toshiba, similar to how Pace would sell receiver designs to other companies, resulting in clone receivers. This was never made to market, and the concept was abandoned.
The 2500N (9F04) was released in 2000, and looked similar to the 2500B but replaced the ST processor with a NEC EMMA processor, which was MIPS based. Pace would go onto use the EMMA processor in their 3000 Sky+ box. Later models of the 2500 would be released in black and silver, and would use the ST5512 processor. These were released in 2001 and began with the 2500S3 model (9F05), along with the 2500S4 (9F06) and the 2500S5 (9F07), which was the first model to have the tuner module integrated onto the main board, rather than using the ZIF design.
The 2600 was a remarkable redesign, integrating the mainboard and power supply board into one unit, allowing for a smaller, more compact design, housed in a while chassis. These boxes were remarkably popular thanks to their powerful processor (Conexant CX22496, similar to what’s used in the Di4000) that was leagues faster compared to other digibox’s, and had a sensitive tuner which made it ideal for reception in Spain or south France. Pace would then release the DS430N, which used the same case design and layout, but would change the processor to an ST 5517. Pace also released the minibox, which used the established 5512 processor. The final Digibox released by Pace would be the DS440N which was recalled and replaced with with the DS445N, which was designed to fix a flaw with the power supply.
Amstrad were an interesting manufacturer of digibox’s, like Pace they had also manufacturer analogue satellite receivers for Sky, and released their first digibox shortly after launch. The DRX100 (4F01) was similar in specifications to the early Pace 2200, both having the ST20-TP2 processor, and having a separate videoguard descrambler. A new revision was released shortly (4F02) which upgraded the CPU to the TP3. All DRX100 boxes were designed and manufactured by Samsung for Amstrad, and the original service manual is Samsung branded.
The DRX200 was released, using the St5512, followed by the DRX300 and later the DRX400, which was manufactured by Technisat and used the Conexant CX22496. Amstrad boxes have had mixed reception by end users with concerns over their stability and long term reliable, with the DRX100 having issues with its tuner module failing. However the later models, along with the DRX500 are considered to be reliable units. Amstrad also made a flow design digibox (DRX550), and had also began manufacturing Sky+ units.
Panasonic had manufactured a select few analogue receiver units and were one of the first announced for Sky Digital, with the TU-DSB20 being released shortly after launch, with it’s ST20-TP3 processor. Unlike other launch models, the DSB20 did not have a TP2 variant. Panasonic would then release the DSB30 in 1999, which saw the introduction of the MN2 processor. Reception to the DSB30 was extremely positive due to its fast operation and response times and its sensitive tuner made it ideal for reception in fringe areas such as Spain. Panasonic followed this up with the DSB31, which featured a new front panel design, but with several cost reductions, and the tuner was downgraded. The DSB31 was not as well regarded as the DSB30.
During this time Panasonic would also experiment with the concept of an IDTV, and would release TV sets with built in digibox’s based on their design, this resulted in the TX, which were digital TV’s with both freeview and sky digital tuners, negating the need for a separate digibox. Sales of this were low and the concept did not take off, and due to the different software being needed to support them correctly, they were unsupported by sky as of 2008, where free replacements to sky+ were offered.
On the digibox side, Panasonic released the DSB40 in 2002, which reused the DSB31 case design but upgraded the processor to n MN2.8. The DSB50 was released in 2004 and used MN3 processor. Panasonic would later cease to produce digibox’s for Sky, and would exit the set top box market following discontinuation of its freeview boxes (DVD/HDD recorders still continued. Panasonic never release a sky+ box.
Sony only made two digibox’s, the VTX-750 and the VTX-760. The 750 featured an ST20-TP3 processor and was released in 2000, whilst the 760 featured a NEC EMMA based processor. Both boxes have a slimline design and feature an optical audio SPDIF output. They did not support Dolby surround sound or AC3 audio. Sony would later ease to provide digibox’s to Sky, likely due to the free box offer, Sony had intended for their boxes to be a premium product.
Since Grundig reused the case design on several models, and released upgraded models using the same model number, its hard to keep track of these boxes, unless you go by the version number. Some models with the /S designation feature S-Video support, something that was later exclusive to the Sky+ boxes.
The first model released was the GDS200, which featured the St20-TP2 processor, with a TP3 revision following up with the 4E02. The GDS200/1 & GDS300 were alter released and used the TP3 processor, with the 200/1 reusing the 200 case design, and the 300 using a new case design, internally they are the same and are known as the 4E02.
Later models were built around the popular ST 5512 processor, and some of these models included S-Video support, the only regular digibox’s to do so. These box’s are known as the 4E04 models, and consisted of the GDS310/2, GDS210/2, GDS210/3 and GDS2000. The final model released was the GDS3000, which had a new front panel design, and was internally known as the 4E05.
All models suffer from poor power supply capacitors, which are notorious for failing from around 18 months of use. This can be fixed by changing the PSU or the capacitors themselves. The PSU problem can also manifest into other issues, such the viewing card not being recognised, or No signal being received on certain or all channels. The PSU issue manifested into the Thomson boxes, since Thomson had bought out Grundig’s satellite division.
Thomson were the direct successor of Grundig, and immediately released several models based on previous Grundig designs, but using an upgraded processor, the ST 5516. These were known as the DSI4101, DSI4210 and the DSI4212. The final digibox from Thomson was the DSI4214, which featured the Conexant 24155 and used the flow design.
Sky IDTV’s (sometimes referred to IDSTV, Integrated digital satellite television) are similar to the Minibox design (Pace 1000) and typically lack the second RF out, although they still have dual card slots, a telephone return path and the RS232 serial port, allowing the use of Sky accessories such as Sky Gamepad and Sky Gnome.
They are initially created as a response to the ONdigital integrated TVs which would have eliminate the need of a set top box in order to access the service. Two manufactures have produced IDTV to date, LG and Panasonic. The LG debuted in 1999 and features an integrated Pace digibox, this was essentially a regular Pace digbox (2200/2400 which was being produced at the time) that was internal to the TV. Panasonic entered the market in late 2000 and unlike the LG was a fully custom design which featured an embedded design. The TV also integrated Freeview, and the digibox’s MPEG2 decoder was reused to decode Freeview channels, however the TV did not support ONdigital, despite the set having a cam slot. A flaw was the TV’s power switch was a physical power switch that when powered off, cut off power to the entire digibox, design wise this could cause problems as the digibox would miss firmware updates and card entitlements since the power was physically cut off and the user would have to wait while the tv listings were loaded, unless the customer had put the TV into standby beforehand.
Whilst having a digibox integrated into a tv may seen desirable for those who want a less complex setup, or have limited space for an additional set top box, they suffer from the following setbacks
- They lock you into a specific TV provider, meaning you cannot use the satellite component of the tv for other satellite services
- If the TV segment breaks down you are essentially locked out of your Sky programming since you cannot disconnect and hook up to another TV
- If there are any major changes to the sky TV service that require an physical upgrade of the digibox or the internal digibox suffers a fault, the idtv component of your TV is made redundant.
- Less flexibility if a customer upgrades to Sky+, with a regular digibox they can relocate it to another tv in another room, not possible with an idtv unless the whole to is relocated. Although if the user takes out a multi-room subscription they can record two programmes via Sky+ whilst watching a third on the IDTV, plus the RF2 out on Sky+ could always be used to playback a watched programme on another TV
- EU laws required IDTVs to support conditional access modules, this means the existing Sky guide software needs to be modified to accommodate the CAM slot
- You cannot output the internet digibox to another source such as a VCR, which makes it difficult to record sky channels to a VCR
After Sky had introduced EPG 3.4.4.b, many IDTV users reported issues when navigating their Sky guide. Since Sky had added more guide genres (Lifestyle, Shopping, etc) but the IDTV’s remained on the older firmware which did not support the new categories. Common issues were gaps in the TV guide, missing channels and general instability whenever the TV guide was used.
Sky had neglected to release EPG version 3.4.4.b to IDTV’s which resulted in TV guide errors since these TV’s were stuck on 3.2.11. Whilst Sky did eventually release an update, in 2008 letters were sent out to customers informing that their IDtv’s were no longer supported and a new Sky+ box would be provided.
Because the IDTV’s use the same IR command set, users that installed regular didbox’s found that the IDTV and digibox would conflict on certain commands, for example if the red button was pressed on the sky remote, both the TV and digibox would react, and in the case of the IDTV, pressing the red button when on an AV/scart input would switch the input to another scart socket, resulting in the TV changing to another input and causing an interruption of viewing. Using Sky+ was an advised workaround since Sky+ remote use a different command set.
|LG||DI-28Z12||Internal Pace receiver|
|Panasonic||TX28DTS1||Includes DVB-T Freeview tuner|
|Panasonic||TX32DTS1||32 inch version of the TX28DTS1|
Launched late 2002 after Sky had introduced multiroom subscriptions, this was a compact styled digibox that had some components removed that may be considered redundant for a second location. Whilst the minibox keeps the message light and interactive card, only one RF out is present, and the digital interface and audio out is removed. Despite the removal of the second RF output, the first was able to provide 9V power to facilitate the use of Sky accessories like the Gamepad. Only one model was produced, Pace 1000. Sky would later use regular digibox as multiroom boxes.
Sky+ was launched in September 2001, and was Sky first PVR product and the UK’s second digital video recorder, the first being Tivo.
Sky+ uses the same OpenTV middleware allowing for compatibility with existing interactive services. XTV is the software used to manage and organise PVR functionality, and is also part of the Sky+ DRM what manages the recorder content on the Sky+ hard drive. To accommodate the new Sky+ features, a new remote control design is used with additional buttons for live pause, fast forward and rewind features.
The first generation of Sky+ was launched in 2001 and debuted with the Pace 3000, Sky+ boxes have the same specifications as regular digibox but with the addition of an IDE hard drive, a second satellite tuner, S-video and optical audio out. All Sky+ models have dual tuners allowing the user to watch one programme whilst another is being recorded, alternately two programmes can be recorded at the same time. When both tuners are in use, a recorded programme can be watched whilst the other two are being recorded. Sky+ supports Dolby Digital and Pro Logic through the provided Optical audio output. S-Video is also provided, previously exclusive to certain Grundig Digibox’s.
PVR2 units were launched in 2004 with the Pace 3100, and the Amstrad DRX180 in 2004. This generation follows the same specifications for the PVR1 units, even the same HDD capacity however with reduction of physical box size and the standardized box design, with the Amstrad being mirrored version of the Pace design. Sky+160, an enhanced version of PVR2 was launched in early 2005 and upgrades the SKY+ capacity to 160Gb capacity, four times the capacity of the regular PVR2 and was made exclusively by Thomson and follows a new design, along with added front and back USB ports, this design would be carried over to the PVR3
PVR3 units saw a significant redesign in terms of features, USB ports were added but are still currently unused. PVR comes with a 160Gb hard disk with 80Gb of disk space is partitioned off for Anytime use, even if the user has upgraded their hard drive. Later PVR3 version units also have the Digital Interface panel removed.
Despite the added features, Sky+ retains backwards compatibility of all Sky accessories such as the Sky Gamepad, Gnome, tvLink. Sky/Open keyboards are compatible but require reprogramming due to the different control set used by Sky+.
All Sky+ models use IDE for the drive interface and can be upgraded by the end user, however certain models have capacity limits due to LBA addressing. Some drives also have certain power requirements hat can cause issues with the boxes power supply, care must be taken to ensure the new hard drive does not add additional stress to the Sky+ power supply. Additional heat generated from the hard drive can also be an issue sine the internal cooling fan is design around the TDP of the original hard drive.
|Amstrad||DRX180||40Gb||PVR2, Mirror image of Pace 3100|
|Thomson||DSI6210||160Gb||Marketed as Sky+160|
|Pace||TDS470N||160Gb (80Gb reserved for Anytime)||PVR3, Supports Sky Anytime, Viewing card slot on the left, Front|
|Amstrad||DRX290||160Gb (80Gb reserved for Anytime)||PVR3, Supports Sky Anytime, Viewing card slot on right|
|Thomson||DSI8210||160Gb (80Gb reserved for Anytime)||PVR3, Supports Sky Anytime, Viewing card slots in the centre|
Exists the current service or menu and returns back to TV viewing, typically the last tuned TV channel, also bring the digibox out of standby
Used to move the cursor onscreen and to select items
takes you back to the previous menu, or cancels an on screen message
Opens the interactive menu, on older versions of software, this would take you directly to the open interactive service.
Typically used to open interactive service if an on-screen prompt is present, can also be reassigned freely by the guide software
Like the red button, can be used to access different applications or functions following an on screen prompt. In Sky Guide, this can be used to for shortcut navigation or to filter the on screen guide
Launched in 1999 to complement the open interactive service, this was a standard sized QWERTY keyboard designed to input full text into the digibox, and was mainly deigned for the email services provided by open such as AOL and BT talk21. It could also be used in the digibox A-Z listings to input text. The keypad can replicate all of the sky remote functions and can be used for regular TV and Sky guide use, and can control a standard TV also.
After Sky active replaced open… the keyboard was rebranded also as the sky keyboard, however the blue colour scheme was kept. The keyboard required 4 AA batteries.
tvlink was an early answer to providing sky tv in multiple rooms and works by splitting the Rf signal into two output, RF1 feeds into the main TV/VCR whilst RF2 is designed to be fed to another room. The rf2 socket on all digibox can provide a 9v power supply which is used to power a TVLINK, which is an external IR sensor that feeds Sky remote commands back to the main digibox.
This setup only allows one Sky channel to be watched on two Tv sets simotainsly, it does not allow two different channels to be watched in two different rooms. Tv sets. It does however allow analogue and digital Freeview channels to be watched as the digibox passes through regular UHF signals. More advanced systems allow the RF2 out to be fed to a loft distribution system where multiple tv’s can be fed from one sky digibox, but only one sky channel can still be watched.
Whilst the tvlink approach was an interesting compromise for multi-room viewing, I’m not sure whilst sky did not provide a digibox that had two tuners and two MPEG decoders that would have allowed two different channels to be watched in another room. This could have been limitations with the Sky videoguard system as that would be technically an early form of card sharing, and there would be issues with Sky channels that require a paired viewing card, such as premium sports an movie channels. The Dish network ViP222 receiver system is an example of such a system that used two LNB feeds and can feed two different channels but used only 1 smart card (Nagravision). Philips also released a DIRECTV equivalent in the US.
This was a portable wireless audio received that allow you to broadcast the audio portion of the digibox to a wireless receiver, allowing it to be used as an alternative to DAB radio by using the radio channels in the Sky guide. Audio from the tv channels can be broadcast also. The sky gnome comes with two devices, the sender and receiver. The sender connects to the digibox via the RS232, audio L/R and the rf2 out connector.
- The audio cable connect to the audio out connecotrs on the digibox
- The Rs232 servial connects to the respective socket on the digibox and allows the digibox to send information releating to the current channel and programme status
- The RF2 out allows the gnome to send commands directly to the digibox by emulating the sky tv link. If a customer already had a tv link device connected, an adaptor had to be requested by the ustomer that would allow the two to connect
- Because of the reliance on the above connections, Sky gnome is not compatable with the minibox, or the later SkyHD units (DRX595, Sky branded Sky+HD)
The receiver unit received the wireless signal from the sender unit. This houses a display showing the current channel information, stereo speakers and front panel controls that emulate a sky remote that allows changing of channels remotely.
The sky gamepad was designed to be used with the Sky Gamestar games and was to enhance the Gamestar experience. Support was introduced with EPG version 3.1a.5. the gamepad consists of the gamepad itself (in single and dual sku variants), the ID clip and the receiver unit that connects to the digibox by the use of the RF2 and the RS232 serial. The RF2 is used to power the unit and uses the RS232 to communicate with the digibox.
The gamepad itself has a directional pad, an A B C D buttons that are coloured based on the sky remote colour buttons and select, backup and help buttons. It can only be used in sky gamepad compatable games, it cannot be used in sky guide or to control regular tv. The gamepad uses IrDA to facilitate the use of ultiple remotes to allow local multiplayer games to be played on one digibox, this is similar to the two way tv developed system used on the Pace DiTV 1000 boxes used on telewest/ntl cable.
Compatible game from an archive article mentions supported games being bust-A-Move, Pong, Centipede, Space Invaders, Pinball and Asteroids. It’s not certain if it was ever compatible with Playjam or the GoPlayTv service.
Basically a compact version of the Sky/Open keypad but embedded into a Sky+ remote. This remote can be opened to revealed a full QWERTY keyboard.
Security of the conditional access system was imperative to the sky digital platform, as the previous sky analogue service was prone to being compromised. This was due to the Videocrypt system being used to scramble pay TV programming. One of the major flaws of sky analogue was the viewing cards used by the service, . The Videoguard system was design to be more resilient to external modification using techniques and learning from the mistakes made by the previous Videocrpt system. One of which was to ensure the conditional access was built into the digibox itself. As when Sky analogue had first launched, the first generation of receivers (Amstrad DRX100) lacked an internal Videoguard decoder, in contrast all Sky digibox mandate for videoguard to be integrated in to the digibox design itself. Initially this was an external process that sat beside the CPU (early Pace 2200, Amstrad DRX100), however in 1999 the ST20TP3 processor was released, which saw the Videoguard conditional access system integrated onto the CPU itself, making It difficult to ‘sniff’ packets exchanged between the two processors. later processors would integrate the MPEG2 decoder, mainly to save cost and reduce design complexity. Many modern digibox employ a system on chip design. Also, unlike other conditional access systems, no Videoguard conditional access modules exist, meaning non Sky receivers cannot be officially used on the service. This has the benefit that Sky customers need to use a digibox to access the Sky TV service, and also allows the guaranteed use on interactive services.
Box office functionality has been improved with Sky digital, not only are there more box office channels which allow for increased showing of movies to occur, but the ability to order films directly from the digibox through the use of the internal modem. Previously the customer had to phone sky box office line to order a film or event, which would require an operator to process the order and send the correct signal to the customers receiver in order for then to decode the programme. With Sky digital, the customer can do all this though the on screen Sky guide, providing the customer had their digibox connected to the phone line.
Interactive services were a new facility provided by digital TV, although in certain cases it can be seen as the successor to teletext/ceefex. With digital TV however, the added return path functional allows the digibox to send data back to Sky, whereas teletext was mainly a one way broadcast medium. This opens up the possibility of WebTV like services such as shopping, email and banking. This was seen as being attractive as the web up until that point was only available on desktop pcs and many e-commerce facility were not yet mature.
Interactive can consist of web like services, where the customer can browse information navigate the service as if it was a web page, Open… was an example of such a service since its main selling point was shopping, home banking and email services, since these sort of service can generate additional revenue,
Game and ‘Apps’ were also a possibility with several game channels launching on Sky. Compared to the game console of the time (Sony Playstation) the digibox was lacking in capability as it could not generate 3D graphics, and with memory contains with the OpenTV virtual machine limited the scope of game on the platform. Many games can be considered as Super-Nintendo/Sega Genesis like in terms on gameplay as all games use a 2D graphics set, however unlike 16bit consoles, games can take advantage of the extended colour pallet provided by the digibox (65.536 colours).
The major drawback with Open was how it was delivered,
- Services were delivered over the satellite feed, albeit at a lower bitrate since many of the services had to be broadcast at the same time, contrast to how Telewest/ntl interactive services worked where the STB load the page it wants in an on demand fashion using its internal cable modem.
- The return path method used by Sky was also a drawback as the digibox had to be connected via the telephone line, which some customers required an additional extension cable
- The modem speed of the early digibox was limited to 9600baud
- Browsing Open shopping services required the customer to be online as this data was not broadcast via the satellite but though the telephone line, whist cost the customer 1.50 for just browsing online
- If someone was using the telephone line, either for talking or for internet use, you could not connect to Open
- The digibox modem was not comparable with ISDN networks
- Some cable providers charged more for calls to Sky
- Interactive services were downloaded and executed to the digiboxes ram, and were wiped out upon exit, meaning the service would have to be downloaded again. Applications also could not store data on the digibox, however the second revision Viewing Card (Yellow house) did allow limited storage space for interactive applications.
The reliance on the phone line limited Open’s scope. Sky could have provided a facility to use WAP or GPRS as an alternative to the phone line which may have helped with customer adoption, although at the time mobile coverage was still not 100% reliable.