Various collation of information about the world first digital satellite service in the US (and likely the world), being launched in 1994.

This page is still work in progress so there may be some mistakes…

DSS Format

As DVB-S had not been fully standardised yet, DirecTV and USSB launched using the DSS protocol for transmission, instead of Digicipher that was used by Primestar. DSS is similar to DVB-S in theory with both supporting QPSK modulation but with DSS using a 127 byte transport packet size, compared to 188 bytes for DVB. Channel information and program description is carried on the Master Program Guide which tells the receivers what channels are available, the frequency parameters and the satellite they broadcast from, whilst DVB used a series of tables known as NIT/PAT/SI. The MPG consumes around 1.3Mbps of bandwidth per transponder.

Master Program Guide

This is the backbone of the DSS system as it contains information relating to the channel mapping of the entire service, and programs currently being broadcast for he next 3/6 hours and any firmware or service updates. The MPG was in use until 201, when it was discontinued in favour of solo APG (Advance program guide) broadcast. This meant the MPG only receivers were no longer capable of receiving the service, and that channel listings were broadcast only in the APG format., regardless of the unit supporting MPEG2/4.

Early receivers were only able to load so much MPG data at once, as a result they were unable to support further channels being added, with some receivers being restricted to channels 800 and below. This was due to the limited memory the early receivers were being shipped with, and the amount of channels being carried on the platform.

The video codec used by DSS was also different as MPEG2 was still in development and was not finalized, MPEG1.5 was used instead with the intention of upgrading to MPEG2 once available. MPEG1.5 was a mix of MPEG1 and 2, best thought of being an alpha version of MPEG2. Dolby AC3 is used as the main audio codec for DSS alongside MP2 Musicam.

The use of DSS meant that only DirectTV approved receiver could only be used to access the service, which meant that DVB and DigiCipher receivers were unable to tune into the service. This also extended to PCI tuners, since the demodulator has to support DSS at the hardware level. This became a problem as receivers become cheaper, as other satellite providers were able to use cheaper demodulators that supported DVB only, whereas DirecTV were limited to chips that could decode DSS (although many of these chips could also decode DVB) Theoretically DirecTV could have switched to DVB via a software update for later receivers, however this may have made the platform way too open, considering the piracy issues DirecTV previously faced with the older access cards.

The DSS setup was quite unique as it seemed to be an open design with DSS being the platform itself, and DirecTV and USSB being separate providers that used the DSS platform to deliver the service. Both companies did not directly complete with each other since each offered their own channel packages, you bought your DSS receiver and dish, installed it and then chose to subscribe to USSB or DirectTV, or both since the channel packages did not overlap – the channels USSB offered were not on DirecTV and vice-versa. DirecTV and USSB would later merge in 1998, and DirecTV would also acquire Primestar, another satellite provider.

Conditional Access

VideoGuard is used as the conditional access system to encrypt DSS programmes for both USSB and DirecTV. This was very similar to the VideoCrypt system used by Sky in the United Kingdom, and was developed by News Datacom (Now Cisco Videoscape, was NDS previously). Like the UK version, the system was frequently compromised which  required the changeover of viewing cards in order to combat piracy. Later access cards mirror the NDS VideoGuard protection used by Sky Digital which has remained secure since its launch in 1998, although there are differences due to the DSS/DVB-S CAS design. The range of access cards (brand of viewing cards) are:

P1 / F Card: Similar to the Sky issue 09 card which was compromised shortly after its introduction, battery cards were released which emulated the 09 card using the Dallas 5002 microprocessor and a Amtel 89c51. DirecTV discontinued the F card in June 1997, rendering these cards useless.

Archive reference

P2 / H Card: Introduced in 1996, contained an ASIC which is a helper chip to make it possible to use a lot more encryption that the main processor is capable of.  these cards were subject to ECM (electronic counter measures) that deceived the card, that were sent by DirecTV.

P3 / Hu Card:


Many early receivers were DSS branded as they were intended to be used either with DirecTV or USSB, and as a result each receiver ran their own guide software, this was in contrast to Sky Digital, where all receivers use the same Sky Guide interface and design. Also unlike Sky, receivers do not follow a standard hardware design, with the video and audio outputs varying across the different models with some only offering composite output, whilst others offer S-Video or component. Many receivers were marketed at different price ranges, whilst Sky mandated that all their Digibox’s were equal and had to follow a strict specification in regards to the rear connections and front panel specification.

Some receivers licensed their software from other manufacturer, and some receivers were rebranded, such as Proscan and General Electric receivers being based on RCA design. RCA was the first manufacturer of receivers in 1994, with Sony and Hughes joining in 1995.

RCA: —

Sony: Released their first model in 1995, the SAT-A1 which came with a wideband data port and low speed data and S-Video out. Two models were released in 1996, the SAT-A2 and SAT-B2 which were similar to the A1 but the A2 came with optical and phono audio out, the B2 was the budget version. These were followed up in 1998 with the A4 and B3 which dropped the dedicated audio outputs, the wideband data port and the RF in, only the IR blaster was supported.

Several models were released in 1999, the Sat-A50 and SAT-B50 which both had S-Video out, but the A50 had an RF remote and optical audio output. The SAT-A55 and B55 were also released that year which were very similar to the previous models, only difference was the bundle dish, the 55 has dual LNB outputs for use with a multi receiver configuration.

Sony would release two models in 2001, the SAT-A65 and B65, the A65 had only one composite output with S-Video, whilst the B65 featured 2, plus optical audio and IR output and In. Both models support Wink interactive.

Hughes:  Released in 1999 the HIRD-D45, that featured an Optical and coaxial output, a 1394 interface intended for a D-VHS player. Hughes would release a variety of receivers in 2000, the HIRD-B1/B2/C2/D1/D11/E1/E61 were entry level models with S-Video and composite output.  The HIRD-B3/B4 models came with a wideband data port and an IR output, with the B4 also featuring a D-VHS 1394 output. The HIRD-D2/D25/E2/E45 are more high end and feature an IR output, with the E45 also coming with optical and coaxial audio output and 1394 interface for a D-VHS recorder.

Hughes OneLineGuide

More models were released in 2001, with the GAEB0A, GAEB0, GCEB0 AND GCEB0A, the latter two has optical out and a mysterious data port. All models support Wink interactive.  The HIRD-E86 was similar but drops the data port in favour of dual composite out. The SD-HBH, HAH-SA and HBH-SA were released in 2003, with the HAH-SA featured optical audio, data port and component video out. The other two receivers just feature S-Video and composite, all three support Wink however.

Panasonic: First two receivers were released in 1996, the TU-IRD10 and 20. Both the same with S-Video and wideband data port but the 20 supports the low speed data port, has an additional composite output and has a IR output. Two more models were released in 2001, the TZ-DBS01 and TZ-DRD100, these models only have a single composite out with no S-Video but do support Wink interactive.

Panasonic Directv TU-HDS

Samsung: released 3 SD models, SIR-300W, SIR-310W and SIR-S60W, first two were released in 2003, whilst the S60 was released in 2001. The S300 and S310 have dual composite output but the 310W has optical, IR and component output. The S60W on the other hard only has composite output. All three receivers have support for Wink interactive.

Philips: The DSR7000, DSX5250 and DSX5350 were released in 2000, the 7000 featured optical audio and an external RF input along with S-video. The 5350 features only S-video, with the 5250 only having composite out. New models were released in 2001, the DSR660 being unique with two tuners, decoders and RF outputs, that allows the receiver to output two channels to different tvs, making it ideal for multiroom distribution, the DSX5150 was also released which only supported one TV and came with S-Video out. DSX5353 and DSX5375 are more basic with only composite output, with the latter supporting a VCR IR blaster.

The DSX5500 and DSX5540 were released in 2002, both featured S-Video, but the 5540 also had digital and coaxial output, along with Wink interactive support and component video out.

Uniden: Released two models, the UDS100 and UDS200. These boxes are unique in that they have a front panel display that displays the time or the channel number. The 200 features S-Video and Wideband data, whist the 100 lacks S-Video.

Toshiba: Two models, TSR101 and 202, both released in 1998. Both featured a wideband data port, but the 202 also has the serial low speed data port and IR in/output.

Optimus: Very little data is known about these receivers, only known models are 5100, 5700 and 5100N.

Mitsubishi: SR-SD1 released in 2000, features low speed data port, S-Video and Optical/Coaxial audio. Also has a D-VHS 1394/Firewire output.

Memorex: MSD5000 released in 1998, features a wideband data port and S-Video. A model MSD5001R was also released but not much information is available.

Hitachi: Several models – HDS100R, HDS200R, HDS210R and HDS220R. Also, a 61HDX98B which may have been an IDTV, Television with a built in DSS receiver. The HDS are probably regular receivers.

DirecTV: From 2004 onwards, DirectTV designed their own receiver units themselves, however they were still manufactured by third parties such as Pace and Humax. All receivers within the series have the same features and utilise the same EPG guide software, similar to Sky Digital in the UK after the introduction of their flow box design

D10-300 (Philips), D10-200 (Samsung), D10-100 (Thomson)

D11-100 (Thomson), D11-300 (Philips), D11-500 (Humax), D11-800 (NEC)

D12-100 (Thomson), D12-300 (Philips), D12-500 (Humax), D12-700 (Pace)

Samsung SL-10D10 – Flip top LCD display with internal receiver.

Common Features

Interactive: Some receivers (2001 onwards) supported Wink technology, where channels could broadcast Wink applications through the DSS data stream. The user would be able to access these services by pressing the wink icon (left) when it appeared on screen, informing the user the current program supported interactive content. Wink was only supported on standalone receivers, Tivo and HD receivers did not support Wink which limited its adoption.

DirecTV Wink menu
Wink Interactive

Wideband Data: This was intended to output the DSS DataStream to an external decoder, such as a HD decoder for use with a HD TV, could also have been used to feed data to an external device such as a game console or computer. Never officially used.

VCR Control (IR out): the receiver can control a VCR using IR, the VCR can be turned on and set to record when a timer programme is set.

IR In: Allows the receiver to be hidden out of view, with an external remote sensor being used to control the box.

Serial Port: Used to control an external device, usage caries on receiver model and manufacturer

Digital Audio Out: Outputs MP2 or AC3 audio to an external audio system

Channel Logo’s: Most receivers supported displaying channel logo within the guide, rather than the channel name. This makes it easier to find and identify the channel.

Digital Video Recorders

Tivo: First generation DVRs were based on Tivo software and implemented the Tivo guide interface, and were manufactured by Hughes, Sony and RCA. Like standalone Tivo recorders, you can schedule recordings, create season passes to record on a regular schedule, create Wishlist’s and thumbs up or down a program to improve the suggestions that get recorded.

Samsung: SIR-4120R – released in 2003

Philips: DSR708 – 2002

Sony: SAT-T60

Hughes: GXCEBOT (2000), HDVR-2 (2002) , SD-DVR40 (2003)

RCA: DVR39, DVR40 DVR120 (2003)

Ultimate TV: In addition to Tivo, there was also Ultimate TV which was based on Microsoft’s Webtv platform that was originally a standalone product for accessing the internet through the TV using the phoneline, however UltimateTV functions as a DVR with dual tuners and an internal hard disk for recording. This was similar to Dish Network’s DVR that also launched that was based on WebTV software (Dish Player). An optional keyboard was available with allowed for easier text entry when browsing the internet. Only RCA (DWD490RE) and Sony (SAT-W60) made UltimateTV hardware.

AOL TV: Never officially launched, this was planned to be based on AOL TV set top box with built in DIRECTV receiver.

DirecTV DVR: DirecTV replaced the TiVo with their own DVR implementation that was designed by NDS, who also designed the Sky+ DVR and used the MediaHighway middleware. This became the foundation of future recorders and receivers DirecTV would release.


R15-100, R15-300,

R16-300, R16-500, 

R22-100, R22-200,

High Definition: DirecTV launched high definition TV in 2000. Since this predated MPEG4-AVC, MPEG2 was used instead which required a significant amount of bandwidth. HDTV receivers also delivered video over component, VGA or later DVI. HDMI was not widespread until around 2004. DirecTV would later launch channels in AVC format and would also upgrade the modulation standard to DVB-S2D, which was based on DVB-S2 but with customised data streams.


RCA: First model was released in 2000 – DTC-100, with optical audio output, and component/VGA HD output. The DTC-210 was released in 2003, and added coaxial alongside optical audio out, and added DVI as the HD output.

Toshiba: Only one HD model the DST3000 released in 2000, outputs HD over component

Zenith: Two models, DTV1080 and HD-SAT520, both feature an ATSC OTA tuner for local terrestrial channels.

LG: Released one model in 2004, LSS-3200A. Features Component, DVI and VGA for HD output.

Mitsubishi: SR-HD1 released in 2000, features Component video out and optical audio.

Panasonic: Only HD model was released in 2000 was the TU-HDS20, outputs HD over component video and supports optical audio out.

Sony: Released their first HD box in 2000, the HD100 which had component and VGA output and had dual S-Video outputs. The SAT-HD200 was released in 2002, and was similar to the HD100 but featured only a single S-Video output, dropped the IR in/out, but added DVI alongside VGA and component. The SAT-HD300 was released a year later and restored the IR in/output, keeping the HD200 added connections.

Samsung: the SIR-TS160 was released in 2002 and has optical and coaxial audio out, and outputs HD over component, DVI and VGA, the SIR-TS360 is the same but was an updated model released a year later.

Philips: DSHD800

Hughes: HTL-HD was released in 2003 and was Hughes first HD receiver, came with component, DVI and VGA HD outputs.

These earlier models only support MPEG2 for high definition, and can no longer receive HD programming since DIRECTV only transmit HD in MPEG4 .