The Personal Jukebox (also known as PJB-100 or Music Compressor) was the first consumer hard drive-based digital audio player. Introduced in 1999, it preceded the Apple iPod, SanDisk Sansa, and other similar players. It was designed and 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 published a software development kit for the unit, which enabled users to develop tools, drivers and applications for different operating systems. History Development The PJB was created as a personal audio appliance prototype by DEC Systems Research Center 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 on the 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". 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, 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