Personal Jukebox
Encyclopedia
The Personal Jukebox (also known as PJB-100 or Music Compressor) was the first commercially sold hard disk
digital audio player. Introduced late in 1999, it preceded the Apple
iPod
and similar players. The original design was developed by Compaq
Research (SRC
and PAAD groups) starting in May 1998. Compaq did not release the player themselves, but licensed the design to HanGo Electronics Co., Ltd.
of South Korea
.
Compaq Research also published a software development kit
for the unit, which enabled users to develop a variation of tools, drivers and applications for many different operating systems.
and Palo Alto Advanced Development group (PAAD). The Project started in May 1998, a month before the Digital Equipment Corporation
merger into Compaq was completed, and a final product was brought to market in November 1999. The PJB was the first hard-disk-based MP3 player made available to the end user (other vendors had announced hard-disk players but had not yet brought them to market).
The "100" in the "PJB-100" name was chosen from the capacity of the original 4.86 GB hard drive in the first Personal Jukebox. With this drive, the unit was expected to hold about 100 popular (45 minute) music CDs encoded at 128 kbit/s. The name was kept for the later models with bigger hard drives, even though these could store a larger number of albums.
The PJB-100 was the first MP3 portable to garner a "Milestone" product designation from MP3 Newswire
, which they defined in their January 2000 review of the PJB-100 as "any product whose breakthrough innovations are so significant, they influence the future course of its industry".
HanGo took the PJB-100 into mass production and introduced it to the public at the Las Vegas COMDEX in November 1999. The first units were sold in a special auction held by MP3.com
, with bids exceeding US$1000. Some winners received their players before the end of 1999. The first auctioned units were hand-built by the Compaq engineers who designed it, and had single-digit serial numbers.
Weight: 280g
(9.9 ounce
s), 304g (10.7 ounces) including battery
Playback: MPEG-1 Audio Layer 3 (MP3
) at bitrate
s of 8 to 320kbit/s
and a sample rate of 44.1kHz (playback support for WAV
is in the firmware, but is not enabled - it was used by the developers before the MP3 decoder was licensed from Fraunhofer IIS).
Audio signal-to-noise ratio
(S/N): >90dB
Audio total harmonic distortion
(THD): <0.1%
Frequency response: 20Hz
to 20kHz
Audio output power: >50mW at 32 ohm impedance
56309 DSP running at 33 MHz. The MP3 codec
(which is about 2 MB in assembly
DSP code) was licensed from Thomson
and Fraunhofer IIS
.
and 1 MB of flash memory
.
The DRAM is used to buffer data (between 8 and 12 minutes of music, depending on the bitrate used for encoding) from the hard disk during playback. The buffer allows the disk to be run only intermittently, preserving battery life. When the hard-disk is stopped, battery life is preserved; the ramp-loaded heads also retract from the disk surface, helping to reduce the possibility of damage.
The flash memory houses the firmware as well as the bootstrap
.
instead of USB for data transmission. USB was used in production models because it was more common than Ethernet on standard home computers in 1998.
of 128×64 pixel
s (2:1 ratio
) at a diameter of 3 inches (7.62 mm). Later versions of the PJB also featured a backlit
display (the backlight comes on when the unit is powered on, or a button is pressed and turns off automatically after a few seconds). The character set the PJB uses internally is Latin-1 (ISO-8859-1), with some minor variations. One of the Compaq developers stated that "it's missing some of the symbols in the range 160 to 255 (because I got bored when I was creating them :-). Upper case accented characters are rendered unaccented, because that looks better within the font's 9 pixel height. There are some strange glyphs in the range 0 to 31, used for the various symbols on the screen."
Volume is adjusted by a wheel on the unit's right side, using a digital
mechanism (it can be turned indefinitely). It also is possible to click or push the wheel, which pauses playback and turns the unit off after about one minute. When the unit is powered off and the wheel is pressed for a few seconds, playback resumes. This also works when the buttons are locked, in case the main controls cannot be easily accessed.
On the same side is also a small switch which locks the unit’s controls (except for the wheel).
. HanGo also sold a more powerful 1600 mA battery to be used in the PJB.
The PJB includes a 5V power supply
which charges the battery and also enables playback without a battery in the unit at all. The charging control circuit for the battery is built into the PJB itself, not the power supply, so the use of a replacement power supply requires only the proper voltage and sufficient current capacity.
Later firmware versions added some of the most requested features:
or FAT32
as is the case with most of the players that were released later, and enables those to be mounted as another drive in an operating system. Instead, a unique file system is used, which, while losing the mounting ability, is optimized for the structure of MP3 files (having a cluster size of 128 kB, which equals about 8 seconds of 128-kBit-encoded MP3-music). Therefore managing actions like defragging become unnecessary. The file system allows the linking of Tracks into various Discs/Sets. Therefore, each track is ideally only stored once on the disc and recurring occurrences of it (for example in playlists or samplers) are just links to the original file. This may help to preserve a good amount of disk space and allows for more tracks to be stored on the disk.
All of this info is stored in the TOC (table of contents). The TOC is stored in a human-readable text-format and can be downloaded, changed with a text editor and re-uploaded to the PJB again. A copy of the TOC is always stored on the unit as well, so errors and damage to the original TOC can usually be fixed.
(Software Development Kit) for the unit and published it under the Open Source
GPL
license in 2000.
device into modern operating systems. Special drivers are required to make the operating system recognize an attached PJB. Drivers for Microsoft Windows
and Mac OS
were included, while drivers for Linux
were developed by the open source community.
-tag will represent which level). It can also encode CDs directly onto the PJB and query the CDDB
for the proper disc/track information. Finally it can update the firmware. If manipulating some values in the Windows Registry
, a hidden menu appears, which can be used to debug and in some cases repair a damaged TOC. The Jukebox Manager does not make use of some of the firmware’s later features, such as downloading tracks back to the computer and does not provide advanced features such as mass-uploading, synchronizing or creating playlists from M3U
-playlists.
s to projects making the PJB's file system mountable as a drive in Linux. Some of the projects include:
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
digital audio player. Introduced late in 1999, it preceded the Apple
Apple Computer
Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...
iPod
IPod
iPod is a line of portable media players created and marketed by Apple Inc. The product line-up currently consists of the hard drive-based iPod Classic, the touchscreen iPod Touch, the compact iPod Nano, and the ultra-compact iPod Shuffle...
and similar players. The original design was developed by Compaq
Compaq
Compaq Computer Corporation is a personal computer company founded in 1982. Once the largest supplier of personal computing systems in the world, Compaq existed as an independent corporation until 2002, when it was acquired for US$25 billion by Hewlett-Packard....
Research (SRC
DEC Systems Research Center
The Systems Research Center was a research laboratory created by Digital Equipment Corporation in 1984, in Palo Alto, California....
and PAAD groups) starting in May 1998. Compaq did not release the player themselves, but licensed the design to HanGo Electronics Co., Ltd.
Remote Solution
Remote Solution Co., Ltd. is an electronics manufacturer located in Gimcheon, South Korea. The company was founded in 1994 as Hango Electronics Co., Ltd. and assumed its current name in 2002....
of South Korea
South Korea
The Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...
.
Compaq Research also published a software development kit
Software development kit
A software development kit is typically a set of software development tools that allows for the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar platform.It may be something as simple...
for the unit, which enabled users to develop a variation of tools, drivers and applications for many different operating systems.
Development
The PJB was created as a personal audio appliance prototype by DEC Systems Research CenterDEC Systems Research Center
The Systems Research Center was a research laboratory created by Digital Equipment Corporation in 1984, in Palo Alto, California....
and Palo Alto Advanced Development group (PAAD). The Project started in May 1998, a month before the Digital Equipment Corporation
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
merger into Compaq was completed, and a final product was brought to market in November 1999. The PJB was the first hard-disk-based MP3 player made available to the end user (other vendors had announced hard-disk players but had not yet brought them to market).
The "100" in the "PJB-100" name was chosen from the capacity of the original 4.86 GB hard drive in the first Personal Jukebox. With this drive, the unit was expected to hold about 100 popular (45 minute) music CDs encoded at 128 kbit/s. The name was kept for the later models with bigger hard drives, even though these could store a larger number of albums.
The PJB-100 was the first MP3 portable to garner a "Milestone" product designation from MP3 Newswire
MP3 Newswire
Founded in 1998, the same year as MP3.com, MP3 Newswire is the oldest active news site devoted to digital media technology. Notable for its series of essays that chronicled the rise of digital music and the Internet’s acrimonious relationship with the record industry, MP3 Newswire initially was...
, which they defined in their January 2000 review of the PJB-100 as "any product whose breakthrough innovations are so significant, they influence the future course of its industry".
Licensing, marketing and distribution
Instead of manufacturing the player themselves, Compaq licensed the design to HanGo, which called it the "Personal Jukebox - PJB-100". The license from Compaq to HanGo was worldwide exclusive - nobody else could license the technology from Compaq during the term of the HanGo license. HanGo granted a distribution agreement to US company Hy-Tek Manufacturing of Sugar Grove, IL in 2001. HanGo rebranded the units sold through Hy-Tek as the "Compressor".HanGo took the PJB-100 into mass production and introduced it to the public at the Las Vegas COMDEX in November 1999. The first units were sold in a special auction held by MP3.com
MP3.com
MP3.com is a web site operated by CNET Networks providing information about digital music and artists, songs, services, community, and technologies. It is probably better known for its original incarnation, as a legal, free music-sharing service, popular with independent musicians for promoting...
, with bids exceeding US$1000. Some winners received their players before the end of 1999. The first auctioned units were hand-built by the Compaq engineers who designed it, and had single-digit serial numbers.
Specifications
Measurements: 150×80×26mm (5.9×3.15×1.0 inches) (W×H×D)Weight: 280g
Gram
The gram is a metric system unit of mass....
(9.9 ounce
Ounce
The ounce is a unit of mass with several definitions, the most commonly used of which are equal to approximately 28 grams. The ounce is used in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems...
s), 304g (10.7 ounces) including battery
Playback: MPEG-1 Audio Layer 3 (MP3
MP3
MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...
) at bitrate
Bitrate
In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....
s of 8 to 320kbit/s
Kilobit
The kilobit is a multiple of the unit bit for digital information or computer storage. The prefix kilo is defined in the International System of Units as a multiplier of 103 , and therefore,...
and a sample rate of 44.1kHz (playback support for WAV
WAV
Waveform Audio File Format , is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs...
is in the firmware, but is not enabled - it was used by the developers before the MP3 decoder was licensed from Fraunhofer IIS).
Audio signal-to-noise ratio
Signal-to-noise ratio
Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined as the ratio of signal power to the noise power. A ratio higher than 1:1 indicates more signal than noise...
(S/N): >90dB
Decibel
The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...
Audio total harmonic distortion
Total harmonic distortion
The total harmonic distortion, or THD, of a signal is a measurement of the harmonic distortion present and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency...
(THD): <0.1%
Frequency response: 20Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
to 20kHz
Audio output power: >50mW at 32 ohm impedance
Electrical impedance
Electrical impedance, or simply impedance, is the measure of the opposition that an electrical circuit presents to the passage of a current when a voltage is applied. In quantitative terms, it is the complex ratio of the voltage to the current in an alternating current circuit...
Digital signal processor (DSP)
The "heart" of the PJB is its Digital Signal Processor. It controls the hard-drive, buttons, LCD, USB interface and handles MP3-decoding for playback. The PJB uses a 24 bit MotorolaMotorola
Motorola, Inc. was an American multinational telecommunications company based in Schaumburg, Illinois, which was eventually divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011, after losing $4.3 billion from 2007 to 2009...
56309 DSP running at 33 MHz. The MP3 codec
Codec
A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
(which is about 2 MB in assembly
Assembly language
An assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
DSP code) was licensed from Thomson
Thomson SA
Technicolor SA , formerly Thomson SA and Thomson Multimedia, is a French international provider of solutions for the creation, management, post-production, delivery and access of video, for the Communication, Media and Entertainment industries. Technicolor’s headquarters are located in Issy les...
and Fraunhofer IIS
Fraunhofer Society
The Fraunhofer Society is a German research organization with 60 institutes spread throughout Germany, each focusing on different fields of applied science . It employs around 18,000, mainly scientists and engineers, with an annual research budget of about €1.65 billion...
.
Memory
The PJB has 12 MB of DRAMDram
Dram or DRAM may refer to:As a unit of measure:* Dram , an imperial unit of mass and volume* Armenian dram, a monetary unit* Dirham, a unit of currency in several Arab nationsOther uses:...
and 1 MB of flash memory
Flash memory
Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data...
.
The DRAM is used to buffer data (between 8 and 12 minutes of music, depending on the bitrate used for encoding) from the hard disk during playback. The buffer allows the disk to be run only intermittently, preserving battery life. When the hard-disk is stopped, battery life is preserved; the ramp-loaded heads also retract from the disk surface, helping to reduce the possibility of damage.
The flash memory houses the firmware as well as the bootstrap
Booting
In computing, booting is a process that begins when a user turns on a computer system and prepares the computer to perform its normal operations. On modern computers, this typically involves loading and starting an operating system. The boot sequence is the initial set of operations that the...
.
Communication interface
To up- and download data, the PJB is equipped with a USB 1.1 Type B connector. Inside is a Philips PDIUSBD12 USB peripheral controller, which averages a raw throughput of about 400 kB/s. Early prototypes used EthernetEthernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
instead of USB for data transmission. USB was used in production models because it was more common than Ethernet on standard home computers in 1998.
Display
The PJB's LCD has a resolutionDisplay resolution
The display resolution of a digital television or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube , flat panel or projection...
of 128×64 pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s (2:1 ratio
Ratio
In mathematics, a ratio is a relationship between two numbers of the same kind , usually expressed as "a to b" or a:b, sometimes expressed arithmetically as a dimensionless quotient of the two which explicitly indicates how many times the first number contains the second In mathematics, a ratio is...
) at a diameter of 3 inches (7.62 mm). Later versions of the PJB also featured a backlit
Backlight
A backlight is a form of illumination used in liquid crystal displays . As LCDs do not produce light themselves , they need illumination to produce a visible image...
display (the backlight comes on when the unit is powered on, or a button is pressed and turns off automatically after a few seconds). The character set the PJB uses internally is Latin-1 (ISO-8859-1), with some minor variations. One of the Compaq developers stated that "it's missing some of the symbols in the range 160 to 255 (because I got bored when I was creating them :-). Upper case accented characters are rendered unaccented, because that looks better within the font's 9 pixel height. There are some strange glyphs in the range 0 to 31, used for the various symbols on the screen."
Hard drive
While flash players could store between 32 and a maximum of 128 MB at the time, the first PJB could store 4.86 GB of music. While the PJB-100 was updated as bigger drives became available, it was also possible for end users to replace the hard drive (although voiding the warranty in that case).Buttons/controls
The PJB has 6 buttons on the front:- Left/Previous/Rewind
- Right/Next/Forward
- Up
- Down
- Play/Pause
- Stop/Power off
Volume is adjusted by a wheel on the unit's right side, using a digital
Digital
A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...
mechanism (it can be turned indefinitely). It also is possible to click or push the wheel, which pauses playback and turns the unit off after about one minute. When the unit is powered off and the wheel is pressed for a few seconds, playback resumes. This also works when the buttons are locked, in case the main controls cannot be easily accessed.
On the same side is also a small switch which locks the unit’s controls (except for the wheel).
Battery and power supply
The PJB is not powered by regular dry cell batteries like most other players at the time of its development, but by a provided HanGo Lithium ion batteryLithium ion battery
A lithium-ion battery is a family of rechargeable battery types in which lithium ions move from the negative electrode to the positive electrode during discharge, and back when charging. Chemistry, performance, cost, and safety characteristics vary across LIB types...
. HanGo also sold a more powerful 1600 mA battery to be used in the PJB.
The PJB includes a 5V power supply
Power supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
which charges the battery and also enables playback without a battery in the unit at all. The charging control circuit for the battery is built into the PJB itself, not the power supply, so the use of a replacement power supply requires only the proper voltage and sufficient current capacity.
Included accessories
Compared to other players, the PJB included a large number of useful high-quality accessories. Details varied from distributor to distributor, but UHU/Portacomp AG included:- Koss Porta Pro headphones
- Leather case with belt clip
- 5 V power supply with converters for European and American power outlets (except UK)
- 1350 mW/3.6 V Li-Ion battery (see the battery section)
- USB 1.1 compliant A-B connector cable
- Cinch-Audio cable 3.5 mm to RCA
- Manual (in German and English)
- CD with drivers and Jukebox Manager software (Windows, Mac OS/OS X, Linux)
Optional accessories
Various accessories were offered by different distributors (among them various headphones and speakers, also for use with other audio hardware than the PJB and replacements for the included accessories):- 1600 mAh Li-Ion Battery
- Waterproof neopreneNeopreneNeoprene or polychloroprene is a family of synthetic rubbers that are produced by polymerization of chloroprene. Neoprene in general has good chemical stability, and maintains flexibility over a wide temperature range...
bag for use of the PJB at a beach or pool - Audio-cassette adapter for playback on car/home stereos
- Swan-neck car-holder
- Various magnetic mounts to attach the PJB within a car
- Power-supply-adapters for car cigarette-lighters
Features and version history
The latest firmware version, which surfaced in December 2003 is v2.3.3-alpha; the latest stable version is v2.3.2, introduced in mid-2001. Initially, the functions provided by the player were basic: when music was played back, selecting another track would immediately start this track and stop the current one; playlists had to be created on the computer; files could only be uploaded to the PJB, but not downloaded back to the computer. New firmware versions came out regularly, but were mostly bug fixes with very few new functions introduced.Later firmware versions added some of the most requested features:
- Files could be transferred from player to PC
- The ability to browse without interrupting playback
- Some (hidden) games were added
File system and table of contents (TOC)
The PJB's disk is not formatted as FATFile Allocation Table
File Allocation Table is a computer file system architecture now widely used on many computer systems and most memory cards, such as those used with digital cameras. FAT file systems are commonly found on floppy disks, flash memory cards, digital cameras, and many other portable devices because of...
or FAT32
File Allocation Table
File Allocation Table is a computer file system architecture now widely used on many computer systems and most memory cards, such as those used with digital cameras. FAT file systems are commonly found on floppy disks, flash memory cards, digital cameras, and many other portable devices because of...
as is the case with most of the players that were released later, and enables those to be mounted as another drive in an operating system. Instead, a unique file system is used, which, while losing the mounting ability, is optimized for the structure of MP3 files (having a cluster size of 128 kB, which equals about 8 seconds of 128-kBit-encoded MP3-music). Therefore managing actions like defragging become unnecessary. The file system allows the linking of Tracks into various Discs/Sets. Therefore, each track is ideally only stored once on the disc and recurring occurrences of it (for example in playlists or samplers) are just links to the original file. This may help to preserve a good amount of disk space and allows for more tracks to be stored on the disk.
All of this info is stored in the TOC (table of contents). The TOC is stored in a human-readable text-format and can be downloaded, changed with a text editor and re-uploaded to the PJB again. A copy of the TOC is always stored on the unit as well, so errors and damage to the original TOC can usually be fixed.
Software development kit
The original developers at Compaq Research designed an SDKSoftware development kit
A software development kit is typically a set of software development tools that allows for the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar platform.It may be something as simple...
(Software Development Kit) for the unit and published it under the Open Source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
license in 2000.
Drivers
The PJB does not integrate itself as a USB mass storageMass storage
In computing, mass storage refers to the storage of large amounts of data in a persisting and machine-readable fashion. Devices and/or systems that have been described as mass storage include tape libraries, RAID systems, hard disk drives, magnetic tape drives, optical disc drives, magneto-optical...
device into modern operating systems. Special drivers are required to make the operating system recognize an attached PJB. Drivers for Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
and Mac OS
Mac OS
Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...
were included, while drivers for Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
were developed by the open source community.
Jukebox Manager (Windows, Mac OS)
The included management tool for the PJB is the Jukebox Manager (the latest Windows version is v1.5.6). It is a pretty basic application which can create/delete/manage Sets, Discs and Tracks (when uploading, the user can choose which ID3ID3
ID3 is a metadata container most often used in conjunction with the MP3 audio file format. It allows information such as the title, artist, album, track number, and other information about the file to be stored in the file itself....
-tag will represent which level). It can also encode CDs directly onto the PJB and query the CDDB
CDDB
CDDB, short for Compact Disc Database, is a database for software applications to look up audio CD information over the Internet. This is performed by a client which calculates a unique disc ID and then queries the database. As a result, the client is able to display the artist name, CD title,...
for the proper disc/track information. Finally it can update the firmware. If manipulating some values in the Windows Registry
Windows registry
The Windows Registry is a hierarchical database that stores configuration settings and options on Microsoft Windows operating systems. It contains settings for low-level operating system components as well as the applications running on the platform: the kernel, device drivers, services, SAM, user...
, a hidden menu appears, which can be used to debug and in some cases repair a damaged TOC. The Jukebox Manager does not make use of some of the firmware’s later features, such as downloading tracks back to the computer and does not provide advanced features such as mass-uploading, synchronizing or creating playlists from M3U
M3U
M3U is a computer file format that stores multimedia playlists. It is supported by many applications.An M3U file is a plain text file that specifies the locations of one or more media files. Each line carries one specification...
-playlists.
Linux projects
There are also various Linux projects operating on SourceForge (some under the banner of the OpenPJB project). These range from Jukebox-Manager-like applications with a GUI for various window managerWindow manager
A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment...
s to projects making the PJB's file system mountable as a drive in Linux. Some of the projects include:
- Jukebox Manager (KDE)
- GNOME/GTK+ GUI Personal Jukebox Manager (GNOME)
- Emacs PJB Manager
- PJB File System for Linux (Kernel 2.3/4, 2.6)
- PJB VFS module (for use with Nautilus)
- pjmirror (written in Perl to synchronize the PJB with data on the PC)
External links
- The new and improved PJB-100 User Group at Yahoo! Groups
- PJB-100 Info Site
- Ultimate PJB-100 FAQ
- Motherboard modification instructions
- pjbExploder (Windows) project home page
- OpenPJB Project multi-platform command line tools and SDK
- Jukebox Manager (Linux/KDE) project home page
- pjbmanager (Linux/GNOME) project home page
- Microsoft Windows 2000 drivers and instructions (download from PJB-100 Yahoo! group, registration necessary)
- Microsoft Windows XP drivers and instructions (download from PJB-100 Yahoo! group, registration necessary)
- Recent Linux 2.6 kernel drivers (download from PJB-100 Yahoo! group, registration necessary)
- File System info - a description of the PJB's file system and other technical info for developers (PDF) - this patent covers one of the key technologies of the PJB: Buffering data into RAM and playing it back from there - this patent covers a different aspect of buffering data in RAM