DreamBox DM500-S Utimate Wave Frontier Toroidal T55 Package

DreamBox DM500-S Utimate Wave Frontier Toroidal T55 Package
DreamBox DM500-S Utimate Wave Frontier Toroidal T55 Package
  • DreamBox DM500-S Receiver with Remote

    • 250 MHz PowerPC Processor (350 MIPS)
    • Linux Operating System, Open Source
    • DreamCrypt embedded
    • 1 x Smartcard-Reader
    • MPEG2 Hardware decoding
    • COM port V.24/RS232
    • 100Mbit full duplex Ethernet Interface
    • 2 Status - LED
    • 32 MByte RAM
    • Unlimited channel list for TV/Radio
    • Channel change in less than 1 second
    • Fully automated channel scan
    • Supports unlimited Bouquet Lists
    • EPG-Support (Electronic Program Guide)
    • Supports multiple LNB switches (DiSEqC)
    • Adoptable OSD (Skin-support)
    • SPDI/F optical TOTX178 AC-3 output
    • 1 x SCART output
    • A/V output (Audio / Video Cinch)
    • External 12V power supply
    • 250 MHz PowerPC Processor (350 MIPS)
    • Linux Operating System, Open Source
    • DreamCrypt embedded
    • 1 x Smartcard-Reader
    • MPEG2 Hardware decoding
    • COM port V.24/RS232
    • 100Mbit full duplex Ethernet Interface
    • 2 Status - LED
    • 32 MByte RAM
    • Unlimited channel list for TV/Radio
    • Channel change in less than 1 second
    • Dimensions: 196 x 130 x 40
  • Genuine Spaun 4x1 DiSEqC Switch
  • DB9 Female to DB9 Female 6 foot null modem serial cable for updating receiver

  • 120 volt US wall connector plug (the regular DM500 only ships with a European connector plug)

  • Wave Frontier Toroidal Dish Package including:

    • 3 units of Reversed DSS Dual Output LNBF
    • 5 units of LNBF Holders**
    • Pole Mount Installation Kit - This kit includes the triangular shaped assembly allowing for simple installation on a roof or to the side of a house. Masonary screws are also included for the option of solidly attaching the dish to any concrete or brick surface

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Dreambox

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Dreambox

From Wikipedia, the free encyclopedia

Jump to: navigation, search
For other uses, see Dreambox (disambiguation).

The Dreambox is a Linux-powered DVB satellite, terrestrial and cable digital television decoder (set-top box), produced by German multimedia vendor Dream Multimedia. Its firmware is officially user-upgradable, since it is a Linux-based computer, as opposed to third-party "patching" of alternate receivers. All units support Dream's own DreamCrypt conditional access (CA) system, with software-emulated CA Modules (CAMs) available for many alternate CA systems. The Dreambox is based on the DBox2 units that were distributed by Kirch Media for its pay-TV services before its bankruptcy; it uses the same Linux-based software originally developed for the DBox2. The built-in Ethernet interface allows networked computers to access the recordings on the internal hard disks on some Dreambox models. It also enables the receiver to store digital copies of DVB transport streams on networked filesystems or broadcast the streams as IPTV to VideoLAN clients. Unlike many PC based PVR systems that use free-to-air type of DVB receiver cards, the built-in conditional access allows receiving and storing encrypted content.

The combination of third-party developers and network connectivity which facilitates card sharing, makes Dreambox use particularly common among enthusiasts and those who intend to obtain services without payment. Third-party software for this purpose is neither officially endorsed nor supported by Dream Multimedia and voids the official warranty; however, unofficial web sites support a very large community of enthusiasts.

In 2007, Dream Multimedia also introduced a non-Linux based Dreambox receiver, the DM100, their sole to date, running on unspecified hardware, but still featuring an Ethernet port and a USB port.[1] The speed of the USB port is not specified, the manufacturer only says it is of "B" type, the one found on peripherals connected to PCs.


Contents

[hide]

[edit] Models

There have been a number of different models of Dreambox available. The numbers are suffixed with -S for Satellite, -T for Terrestrial and -C for Cable:

DM 7000 56x0 500(+) 600 7020 7025(+) 800 8000
Production discontinued discontinued 500+ avail. available available 7025+ avail. available forthcoming
SoC STB04500 STB04500 STBx25xx STBx25xx STB04500 Xilleon 226 ? ?
CPU type PPC PPC PPC PPC PPC MIPS MIPS MIPS
CPU (MHz) 252 252 252 252 252 300 300 400
RAM (MiB) 64 64 32 96 96 128 256 256
Flash (MiB) 8 8 8 32 32 32 64 128
Flash type NOR NOR NOR NAND NAND NAND ? NAND
DVB 1 × S 1 × S 1 × S 1 × S / C / T 1 × S 2 × S / C / T S+S2 / C / T ?
HDTV No No No No No Partial Yes Yes
CI 1 2 0 0 1 1 0 4
CF 1 0 0 0 1 1 0 Yes
SC 2 1 1 1 2 2 1 2
USB 1.1 No No No 1.1 1.1 2.0 2.0
LAN (Mbit/s) 100 100 (DM5620) 100 100 100 100 100 100
HDD 3.5" No No 2.5" 3.5" 3.5" 2.5" 3.5"+DVD
ATA parallel No No parallel parallel parallel serial serial
RF mod. No Yes No No Yes Yes No ?
SCART 2 2 1 1 2 2 1 2
DVI 0 0 0 0 0 0 1 1
Display LCD LCD No No LCD OLED OLED OLED

[edit] DM 7000 (discontinued)

DM 7000-S
DM 7000-S

The DM 7000 is based around the IBM STB04500 controller, featuring a PowerPC processor subsystem and hardware MPEG decoding, has 64 MB of RAM, 8 MB of NOR flash memory (directly executable), a Common Interface slot, a dual smart card reader, a Compact Flash card reader, a USB 1.1 port, and an IDE (also known as PATA) interface for attaching an internal 3.5" hard disk drive to convert the unit into a digital video recorder. Accepts only 220 V AC power.[2]

Because the boot loader resides in flash memory, this model may require the use of a JTAG in case of bad flashing which destroyed the boot loader. However, a bad flash will occur under rare scenarios, and rarely - near never will you need a JTAG.

[edit] DM 5600, DM 5620 (discontinued)

There was a DM 5600 and also a DM 5620 model. The only difference being that the DM 5620 included an Ethernet port. Otherwise, the DM 56X0 models were a cut down version of the DM 7000 without an IDE interface. They did, however, include an RF modulator allowing them to be used with older TVs that lack a SCART connector.

[edit] DM 500 (discontinued), DM 500+

The DM500 is the successor to the DM5620 and is the smallest and cheapest Dreambox. It is based around an IBM STBx25xx Digital Set-Top Box Integrated Controller, featuring notably a 252 MHz PowerPC processor subsystem, hardware MPEG 2 video and audio decoding and smart card interfaces. The DM500 features 32 MB of RAM and an unspecified amount of Flash memory, probably 8 MB, given that firmware images are about 5 MB. It has the standard features of a free-to-air (FTA) satellite receiver, plus extensive Fast Ethernet networking connectivity and a single smart card reader. It does not feature a 7-segment LED display, normally found in other FTA decoders.

Also has the ability to be used on Digital satellite, cable and terresteral broadcasts (also known as DVB-S, DVB-C, DVB-T).

Counterfeit versions of the DM500-S are wide spread[3] and are often sold at a price close to the original.[citation needed]. As a result, Dream Multimedia introduced the DM500+, with changes to try to prevent further counterfeiting. The DM500+ model has 96 MB of RAM instead of 32, and 32 MB of NAND flash instead of 8 of NOR flash. This makes it similar to the DM600 PVR model. It is only available in DVB-S versions.

There also exist legal clones, built around the same commodity IBM SoC chip and hence having identical or slightly superior features but not sold under the Dreambox brand name, eg. the Envision 500S (with 48 megabytes of RAM instead of 32, also available in a 500C cable version), the Eagle box or the Linbox 5558. They have a retail price approaching the one of non-Linux receivers, generally a fraction of the Dreambox 500 price.

On April 2008, an unofficial firmware group called Gemini installed a time bomb in their firmware, causing flash corruption on clone DM500-S receivers.

[edit] DM 7020

The DM 7020 is essentially an updated DM 7000 with 96 MB of RAM, 32 MB of NAND flash (disk-like) and an RF modulator. Changes were also made on the software side, utilizing Open Embedded [1] for the base Linux operating system.

Because the flash memory of this model is not directly executable, the primary boot loader resides in ROM and can recover corrupted secondary boot loader in flash by loading from the serial port.

[edit] DM 7025, DM 7025+

The DM 7025 is similar to the DM7020 but with the ability to add a second "snap-in" tuner that makes it possible to watch one program while recording another. It is possible to change the tuner module, selecting between any two of Satellite, Terrestrial or Cable versions.

Internally, it features a Xilleon 226 system-on-a-chip from ATI, integrating a 300 MHz MIPS CPU core instead of the traditional PowerPC found in other models, and has 128 MB of RAM. It uses Enigma2, this is a complete rewrite of the original Enigma GUI, and is still going through growing pains as features that were present in Enigma are added to Enigma2. Enigma2 is Python-based instead of C code.

The DM 7025 has the ability to decode MPEG 2 HD as well. Unfortunately, it must downconvert this to 480i to display it. 720p works great but 1080i can stutter during fast motion scenes.

The DM 7025+ model features an OLED display instead of an LCD one, an eject button on the Common Interface slot and improved power supply.

[edit] DM 600 PVR

The DM 600 PVR is the same small size as the DM 500 but includes an IDE interface allowing to add an internal 2.5" laptop-type hard disk drive. On the outside it adds an S-Video output connector and an analog modem port. It is built around the same IBM STBx25xx integrated controller, but features 32 MB of flash and 96 MB of RAM, of which 64 MB are user-accessible. It is possible to change the tuner module, selecting between Satellite, Terrestrial and Cable versions. There is still just one SCART connector and no 7-segment LED display, just 2 status LEDs. The provided remote control unit is the same one supplied with the 7000, 7020 and 7025 and allows one to control the TV set as well.

[edit] DM 800 HD PVR

This is essentially a high definition version of the DM 600 PVR, featuring a single pluggable DVB tuner (S/S2, C or T), a 300 MHz MIPS processor, 64 Mbytes of Flash memory, 256 Mbytes of RAM and room for an internal SATA 2.5" disk.
It also features one DVI, two USB 2.0 and one 10/100 Mbit/s Ethernet interfaces.
It has an OLED display.

[edit] DM 8000 HD PVR

This is the long-awaited high definition PVR. Like the DM-7025, it is supposed to support pluggable tuner modules. In addition to High Definition, it should also have a DVD drive and USB 2.0.

This product has been announced at beginning of 2007, but its release date has slipped. The planned features have been revised as well. Originally, this model was supposed to have 128 MB of RAM (now 256), 32 MB of flash (now 128) and a 300 MHz processor (now 723 MHz IBM Processor). Other Linux-based HD receivers have become available in the meantime.

[edit] Software

The Linux-based software used by Dreambox was originally developed for DBox2, by the Tuxbox project. The Dbox2 was a proprietary design distributed by KirchMedia for their pay TV services. The bankruptcy of Kirch Media flooded the market with unsold boxes available for Linux enthusiasts. The Dreambox shares the basic design of the DBox2, including the Ethernet port and the PowerPC processor.

The factory-installed distribution on the Dreambox is mostly available under the GNU General Public License (GPL) and uses standard Linux API's, including Linux DVB API and Linux Infrared Remote Control (LIRC). This configuration encourages enthusiasts to modify its functions, particularly in the form of so-called images such as PLi, View, Gemini, Neutrino, Colosseum.

In addition, unofficial third-party conditional access software modules (CAMs or emulators) are widely circulated on the Internet that emulate the CA systems developed by VideoGuard, Irdeto Access, Conax, Nagravision, Viaccess and other proprietary vendors. Many Dreambox owners use these softcams in conjunction with card sharing software to access pay TV services without a subscription card inserted in every connected box. This practice may be illegal in some jurisdictions.

There are also many 3rd party addons & plugins available that will extend the functionality of the Dreambox too. Some plugins are model specific, while others run all boxes. Plugins such as Jukebox and SHOUTcast playback, also external XMLTV guides, a web browser are available, and a VLC media player interface for on demand streaming media. Games are also abundant like PacMan and Tetris.

[edit] Notes

  1. ^ Dream-Multimedia-Tv GmbH
  2. ^ In order to use model DM 7000 within North America, a stepup transformer is needed to run the Dreambox on 220 V. This is the only model Dreambox that requires this when used in North America.
  3. ^ http://www.dream-multimedia-tv.de/english/dm500_copy_eng.php Plagiarisms of the Dreambox DM500-S are in the market

[edit] See also

[edit] External links

Retrieved from "http://en.wikipedia.org/wiki/Dreambox"

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DM 7000 (discontinued)

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Hertz

From Wikipedia, the free encyclopedia

(Redirected from Mhz)
Jump to: navigation, search
For other uses, see Hertz (disambiguation).
"MHZ" redirects here. MHZ may also refer to the IATA airport code for RAF Mildenhall.
"MHz" redirects here. MHz may also refer to MHz Networks.

The hertz (symbol: Hz) is a measure of frequency, informally defined as the number of events occurring per second. It is the basic unit of frequency in the International System of Units (SI), and is used worldwide in both general-purpose and scientific contexts. Hertz can be used to measure any periodic event; the most common use for hertz is to describe frequency of rotation, in which case a speed of 1 Hz is equal to one cycle per second.

More formally, the unit hertz is defined by the International System of Units (SI) such that the hyperfine splitting in the ground state of the caesium 133 atom is exactly 9 192 631 770 hertz, ν (hfs Cs) = 9 192 631 770 Hz.[1]. Equivalently, 1 Hz = 1⁄9,192,631,770 ν (hfs Cs). This definition is derived from the SI definition of the second. The base unit for hertz is s-1 (also called inverse seconds, reciprocal seconds). As hertz is commonly used to measure rotational speed, the base unit is sometimes represented as cycle/s.

In English, hertz is used as both singular and plural. As any SI unit, Hz can be prefixed; commonly used multiples are kHz (kilohertz, 103 Hz), MHz (megahertz, 106 Hz), GHz (gigahertz, 109 Hz) and THz (terahertz, 1012 Hz). One hertz simply means one cycle per second (typically that which is being counted is a complete cycle); 100 Hz means one hundred cycles per second, and so on. The unit may be applied to any periodic event—for example, a clock might be said to tick at 1 Hz, or a human heart might be said to beat at 1.2 Hz. The frequencies of aperiodic events, such as radioactive decay, are expressed in becquerels.

To avoid confusion, periodically varying angles are typically not expressed in hertz, but rather in an appropriate angular unit such as radians per second. A disc rotating at 60 revolutions per minute (RPM) can thus be said to be rotating at ≈6.283 rad/s or 1 Hz, where the latter reflects the number of complete revolutions per second. The conversion between a frequency f measured in Hertz and an angular frequency ω measured in radians/s are:

ω = 2πf and f = \omega/(2\pi) \,.
This SI unit is named after Heinrich Hertz. As with every SI unit whose name is derived from the proper name of a person, the first letter of its symbol is uppercase (Hz). When an SI unit is spelled out in English, it should always begin with a lowercase letter (hertz), except where any word would be capitalized, such as at the beginning of a sentence or in capitalized material such as a title. Note that "degree Celsius" conforms to this rule because the "d" is lowercase.
— Based on The International System of Units, section 5.2.

Contents

[hide]

[edit] History

The hertz is named after the German physicist Heinrich Hertz, who made important scientific contributions to electromagnetism. The name was established by the International Electrotechnical Commission (IEC) in 1930.[2] It was adopted by the General Conference on Weights and Measures (CGPM) (Conférence générale des poids et mesures) in 1960, replacing the previous name for the unit, cycles per second (cps), along with its related multiples, primarily kilocycles per second (kc/s) and megacycles per second (Mc/s), and occasionally kilomegacycles per second (kMc/s). The term cycles per second was largely replaced by hertz by the 1970s.

The term "gigahertz", most commonly used in computer processor speed and radio frequency (RF) applications, can be pronounced either /ˈgigaˌhɝts/, with a hard /g/ sound or /ˈʒɪgaˌhɝts/ or /ˈdʒɪgaˌhɝts/, with a soft /ʒ/ sound at the beginning of the word. The prefix "giga-" is derived directly from the Greek "γιγας" and hence the preferred pronunciation is /ˈgɪga/. Some electrical engineers use /ˈdʒɪga/, by analogy with "gigantic".

[edit] Applications

[edit] Vibration

Sound is a traveling wave which is an oscillation of pressure. Humans perceive frequency of sound waves as pitch. Each musical note corresponds to a particular frequency which can be measured in hertz. An infant's ear is able to perceive frequencies ranging from 16 Hz to 20,000 Hz; the average human can hear sounds between 20 Hz and 16,000 Hz.[3] The range of ultrasound, infrasound and other physical vibrations such as molecular vibrations extends into the megahertz range and well beyond.

[edit] Electromagnetic radiation

Electromagnetic radiation is often described by its frequency—the number of oscillations of the perpendicular electric and magnetic fields per second—expressed in hertz.

Radio frequency radiation is usually measured in kilohertz, megahertz, or gigahertz; this is why radio dials are commonly labeled with kHz, MHz, and GHz. Light is electromagnetic radiation that is even higher in frequency, and has frequencies in the range of tens (infrared) to thousands (ultraviolet) of terahertz. Electromagnetic radiation with frequencies in the low terahertz range, (intermediate between those of the highest normally-usable radio frequencies and long-wave infrared light), is often called terahertz radiation. Even higher frequencies exist, such as that of gamma rays, which can be measured in exahertz. (For historical reasons, the frequencies of light and higher frequency electromagnetic radiation are more commonly specified in terms of their wavelengths or photon energies: for a more detailed treatment of this and the above frequency ranges, see electromagnetic spectrum.)

[edit] Computing

In computing, most central processing units (CPU) are labeled in terms of their clock speed expressed in megahertz or gigahertz (109 hertz). This number refers to the frequency of the CPU's master clock signal ("clock speed"). This signal is simply an electrical voltage which changes from low to high and back again at regular intervals. Hertz has become the primary unit of measurement used by the general populace to determine the speed of a CPU, but many experts have criticized this approach, which they claim is an easily manipulable benchmark.[4] For home-based personal computers, the CPU has ranged from approximately 1 megahertz in the late 1970s (Atari, Commodore, Apple computers) to nearly 4 GHz in the present. This can be increased even further by increasing the frequency of the CPU (overclocking) in the BIOS or other software. (Likewise, speed can also be decreased, or underclocked.)

Various computer buses, such as memory buses connecting the CPU and system random access memory (RAM), also transfer data using clock signals operating at different frequencies in the megahertz ranges (for modern products).

[edit] Order of magnitude

Frequency (Hz) Name Unit Frequency (Hz) Name Unit
100 Hertz Hz


101 Dekahertz daHz 10–1 Decihertz dHz
102 Hectohertz hHz 10–2 Centihertz cHz
103 Kilohertz kHz 10–3 Millihertz mHz
106 Megahertz MHz 10–6 Microhertz µHz
109 Gigahertz GHz 10–9 Nanohertz nHz
1012 Terahertz THz 10–12 Picohertz pHz
1015 Petahertz PHz 10–15 Femtohertz fHz
1018 Exahertz EHz 10–18 Attohertz aHz
1021 Zettahertz ZHz 10–21 Zeptohertz zHz
1024 Yottahertz YHz 10–24 Yoktohertz yHz

[edit] Frequencies not expressed in hertz

Even higher frequencies are believed to occur naturally, in the frequencies of the quantum-mechanical wave functions of high-energy (or, equivalently, massive) particles, although these are not directly observable, and must be inferred from their interactions with other phenomena. For practical reasons, these are typically not expressed in hertz, but in terms of the equivalent energy.

[edit] References

  1. ^ BIPM definition
  2. ^ IEC History
  3. ^ Dominant spectral region
  4. ^ Good Riddance, Gigahertz

[edit] See also

[edit] External links

Retrieved from "http://en.wikipedia.org/wiki/Hertz"

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