Showcase: Jukebox II

My second jukebox

The Advantech industrial PC board PCM-5820 (200Mhz Cyrix Media GX), is a highly integrated Pentium compatible PC board with the size of a 3.5" harddisk. A fan is actually not needed in this configuration. But I'm a little bit paranoid, and I don't want my electronic parts to be overheated. It's a 12V fan powered at 5V, so that it makes no audible noise.

The silent 45GB Quantum harddisk can store about 800 albums - it is half full now.

This jukebox can play and record CDs with it's integrated slim line CD-ROM drive. But it remains permanently attached to the local network in order to have internet access and to synchronize its content with my main GiantDisc server.

The jukebox also features a 2x16 backlit text LCD, which displays the currently played track and the playtime. The most basic play controls for the current playlist are controlled by a small keyboard with 8 keys. The LCD and keyboard are attached to the parallel port and are controlled by drivers of the LCDproc package, which is supported as of GiantDisc version 1.12. For more information about the LCD refer to the manual.

The case is a used single SCSI CD-ROM case including a switched power supply. You can deduce from that, that the new electronics parts (pc, hd, cdrom) occupy exactly the volume of a full sized CD-ROM drive. I gor the case from my local second-hand dealer for a few dollars.

As power supply, the original built-in switched power supply of the CD-ROM case is used. It powerful enough, but unfortunately still occupies more than one third of the case and constantly dissipates a few watts. A small PCB contains a simple headphone amplifier, based on a Philips TDA7050 low voltage stereo amplifier. See PCB Details.

The system runs GNU/Linux RedHat 7.2. I'm very happy with the journalling ext3 filesystem, because it is much more robust on accidental power interruptions.

The onboard sound quality is good, however the standard SB driver produced occasional hiccups. With the commercial opensound driver from 4Front Technologies everything worked well.
(Well, there was a problem. When I was playing sound files from a process that was not spawned from a shell but from a cron job or rc.local the sound data was "running" through the sound device at full decoding speed. Strange enough, the solution was to change the order of the directories in the PATH variable of the user music to $PATH:$HOME/bin.

Rolf Brugger, July 2002.

Prototype without case and CD-ROM drive

Power input is a regulated 12V/24W source from a very small switched wall adapter. Right next to the harddisk a 10W DC/DC converter (the small red box) generates regulated 5V for the disk and the board.

This version of the jukebox did not have recording capabilities. Therefore it was almost permanently attached to my main GiantDisc server over the local network. All tracks were copied to it using the GiantDisc synchronize utility.