The system hardware consists of a AMD Duron 800Mhz processor, Gigabyte 7IXE4 motherboard with AMD 750 chipset and 128MB of SDRAM. Now that the system does quite a bit more than simply playing mp3's as with my previous system, the extra grunt of the 800Mhz CPU starts to become quite an advantage especially with DivX playback and graphic intensive audio visualization plugins. Duron CPUs have always worked great for the price and give plenty of grunt, whilst the Gigabyte motherboard was previously in my desktop system before an upgrade and had worked flawlessly in that time - nothing too flash, but for such a system it doesn't need to be. 128MB of system RAM provides more than enough headroom for the OS and application software - considering that only 1 task is performed at a time (mp3 or divX playback).

With the increased storage requirements needed for video/DivX playback a 40GB 5400rpm IBM IDE hard drive is being used. The drive is installed into a removable hard disc bay which is then transferred between the car and my desktop PC for audio and video uploads, scandisks and software updates. I find this system works well compared to using a network card/LAN or other data transfer method due to the high speed of file transfer using direct hard disc copying. As the images show the hard drive bay simply slots into the front of the case without any extra type of shock absorption method which I have found to be of little use or need anyway. With the unit placed in the car the hard drive is on its side, which in case of a hard shock due to a bump/pothole/other the hard drive heads will not smack into the drive platters which will/may avoid any physical damage to the hard drive. To this day I have never had music skip whilst driving, which could not be said for a lot of commercial car in-dash CD units, nor have I suffered a bad sector on the hard drive.

The custom system case was constructed using 5-6mm plywood and liquid nails, which gives a very light and surprisingly strong enclosure as well as the advantage of being very easy to cut/shape during construction. To give it some looks the case was then covered using good quality grey automotive carpeting as used on the floor of the swifts hatchback, which I feel gives a good look and some protection from knocks and bumps. Instead of exposing all motherboard connections for cabling/hookups I decided to only extend required sockets to the side of the case to keep things neat and simple to hookup. The motherboard, modified ATX PSU and inverter are all bolted to the floor of the enclosure to keep things solid and in place. To aid with ventilation and cooling of the system a 40mm fan was fitted to the back acting as an exhaust to help expel warmer air from inside the case. Should help to 'summer proof' the system at the very least.

The system is powered via a 140W Jaycar inverter and a standard 300W ATX computer power supply. Both items have been removed of their casings to reduce their size and then mounted inside the case to keep the entire mp3car system self contained and neat. The PSU circuit board has been mounted to the base of its original metal casing which made it easy to ground it back to the car body - which is very important to avoid electrical noise.

In addition the ATX supply had its mains input circuitry slightly modified to perform better with the inverters power output. This improves the efficiency of the supply and stops buzzing of the PSU which would otherwise end up in the audio output. The inverter was directly wired into the PSU, keeping the high voltage/240V path as small as possible, internal to the system case plus eliminating ugly mains plugs/sockets from the setup.

Power to the entire system (including amp/pre-amp) is supplied from monster 4GA DC power cable directly from the battery, and grounded back to the car chassis in the boot using another length of 4GA. The system is switched on/off via a 30A horn relay, controlled through a toggle switch next to the drivers seat (as shown to the right) which in addition controls power to the pre-amp/amp. With this setup I can very quickly cut power to the system as a whole and ensure that no extra drain is present on the battery.

To turn the computer on I originally extended a push button switch from the soft-power terminals on the motherboard to the front of the car alongside the inverter relay switch. Since then I have changed motherboard BIOS settings to automatically power up the system 'after power failure', which eliminated the need for the soft power push button this time round.