Electronic Design

EiED Online>> Building A Mini-ITX System

It was time for a Christmas project so I was delighted when VIA Technologies provided a pair of EPIA motherboards to build some systems from scratch. I have been building PCs from the ground up since the old Z80 S-100 days. Back then systems required many boards. Today we come to the other end of the spectrum where one board does it all.

The article takes a step-by-step approach with plenty of photos to show how anyone with a little computer expertise can build a very compact system. These systems can be used as is but they can also be the basis for a custom product line like a service gateway or a point-of-sale system.

The two Mini-ITX boards from VIA include the ML8000A and the PD10000. They are targeted at different applications so I utilized each for one of their intended markets. The ML8000A is a typical PC system with Fast Ethernet, four USB ports, graphics and audio support. On the other hand, the PD10000 has two Fast Ethernet ports and an LVDS (Low Voltage Differential Signaling) connector that can handle interfaces like and LCD panel. It also has four serial ports that make it ideal for many applications such as a gateway or a point-of-sale terminal server.

The boards were used to create two systems that are essentially identical except for the features of on the motherboard. The first is a PC based on the ML8000A. The second is a file server/gateway using the PD10000. The boards support network booting so it is possible to build a diskless system.

The Morex case used in the system was obtained from Logic Supply. Logic Supply can also provide all the other components used in the project. It's a great source for Mini-ITX cases, peripherals, and motherboards including those based on Intel's Pentium 4.

The other main components were the Teac slimline DVD Writer and Seagate's 100-Gbyte Momentus 2.5-in. hard-disk drive. Both are found in many laptops. These are the only style drives that will fit into the Morex case. Larger cases are available for the Mini-ITX form factor and these can handle conventional 3.5-in. hard drives and optical drives.

Teac slimline DVD Writer handles CDs and DVDs. It can write CD-R/RW media as well as DVD-R/RW media. The Morex case came with an adapter as the Teac drive, as do all other slimline drives, and it has a single connector for audio, power, and the IDE interface. The motherboards have separate connectors for each. I had to dig up a CD audio cable because none was included with the case.

Seagate's Momentus 2.5-in. hard-disk drive was the largest of the series. The series runs at 5400 rpm and they are extremely quiet. This is especially important if you decide to go with one of the slower, fanless processors. It does allow for an essentially silent system. The fans used on the systems I built were very quiet, especially compared to most PC systems I have built. The Momentus has a 5-year warranty and is designed to handle physical environments that are harsher than a desktop system will ever encounter.

Getting Started
Putting the system together is actually quite easy if you have the proper tools, peripherals, and software. First, you will need fine and regular head Philips screwdrivers. You can use the former to mount the slimline optical drive and its adapter. You should also have a bowl or container for the screws. Some will be very hard to replace if they are lost.

You will need a PS/2 keyboard or a USB keyboard with a PS/2 adapter. The BIOS defaults have the USB keyboard support disabled for some unknown reason. This makes it hard to check out the BIOS if you have only a USB keyboard. The PS/2 support is not necessary after the system is setup, although you might want to continue to use it to leave the USB ports for other purposes. A USB or PS/2 mouse is handy for setting up most software used in these projects.

I decided to spread the software chores around. For the PD10000 system I went with Novell's SUSE Linux. I had employed this on a gateway before so I was familiar with the software. For the ML8000A I used a dual boot environment with Mandrake Linux and Microsoft Windows XP Professional. Although I choose a number of operating systems for this test, any one will perform the functions necessary for any of the projects. It is a better idea to use Windows Server 2003 for the file server/gateway because it has better user management, among other features, than Windows XP.

The systems are also equally suitable for those used with embedded operating systems, including Embedded Windows XP, a host of Linux distributions, and more than a handful of real-time operating systems. The next few sections take a look at the hardware and software installation. I have included a table of figures in the next section in case you want to run through the various photos.

Table Of Figures
This particular article has a lot of photos. I reference them in the next section but here is a table of all the figures in case you want to just look at the pictures.

Figure 1 EPIA ML8000A motherboard top view
Figure 2 EPIA motherboard PD10000 top view
Figure 3 Rear view of ML8000A and PD10000
Figure 4 Morex 3677 case in vertical position
Figure 5 Interior of Morex 3677
Figure 6 Morex 3677 case with power supply
Figure 7 Morex 3677 compared to a standard CD-ROM drive
Figure 8 Seagate 100Gbyte Momentus 2.5-in. hard disk and adapter cable
Figure 9 Slimline Teac CD/DVD Writer with detached adapter
Figure 10 Mounting motherboard in case
Figure 11 Connecting power cable
Figure 12 Plugging SDRAM into motherboard
Figure 13 Drives mounted on carrier frame before installation in the case
Figure 14 Completed system interior

Building The Mini-ITX System
The VIA EPIA ML8000A (Fig. 1) and PD1000 (Fig. 2) have the same 14- by 14-cm Mini-ITX form factor. Their peripheral complement is slightly different, as are the connectors on the rear of the system (Fig. 3). They both have four mounting holes and each comes with a matching backplate the fills the rectangular hole on the back of a Mini-ITX case like the Morex 3677 case (Fig. 4) used in the projects. The case can be mounted horizontally or vertically.

First, remove the top cover of the case to reveal the interior (Fig. 5). The dc-dc power converter is already mounted near the front of the system. It works with an external power supply (Fig. 6). Remove the top frame/bracket held on with four screws. The slimline drives will be mounted on the top frame/bracket. Refer to Figure 7 to view the difference in size between the case and a full-size optical drive. It would simply not fit into this case.

Take a look at the cables and drives before installing them. The hard-disk cable that comes with the case (Fig. 8) must be used with the Seagate Momentus hard-disk drive. The power connection goes on the left side of the drive as viewed from the rear. Do not connect the cables to the drives. The process is to first connect the cables to the motherboard, mount the drives on the bracket, install the bracket, and then connect the cables to the drives. You will have to disconnect things if you do it in the wrong order. Bolt the hard-disk drive to the bracket at this time.

Note the orientation when installing the hard disk on the bracket. It can actually go in either direction but try to put the connector end away from the PCI connector. This will keep the cable away from that side when it is installed. Of course, you probably won't need the PCI slot unless you are using a custom design card.

Next, find the optical drive adapter board (Fig. 9) that comes with the case to the back of the Teac CD/DVD Writer drive. It uses a pair of tiny screws provided with the adapter. Make sure everything is secure before proceeding. Make a note of pin 1 on the adapter for when you later connect the IDE cable to the adapter.

The motherboard can now be installed (Fig. 10). But first put the backplate into the hole in the rear of the case. Bolt down the motherboard using the four supplied screws. It is a snug fit so make sure everything lines up before tightening the screws.

Connect all the cables from the front panel and power supply to the motherboard (Fig. 11). The USB front panel cable is keyed making it easy to install. The power and hard-disk LED cables give you 50/50 chance of getting the polarity correct so be prepared to swap them if the lights remain dim. Also connect the IDE cable, one handles both drives, and the audio cable. The CD-based documentation will help although the small quick start guide may be all that an expert requires. The one item you may need to locate is the connector for the side mounted case fan.

Don't forget to plug in the DDR SDRAM (Fig. 12). The boards only have one slot so make sure you get the right amount of memory up front. It is relatively easy to change but this is essentially a non-upgradable system. Then again, the only upgrade I have ever done with most systems is to replace the hard disk.

Finally, install the disk carrier frame bracket (Fig. 13). Thread the IDE cable through the hole and then hold down the bracket. Be careful to route the power supply cable so it does not interfere with the CPU fan. Connect the audio cable and DVD drive power supply connection first. Next connect the IDE cable center connector to the DVD drive. Last, connect the power connector to the hard-disk drive cable and connect the end of the IDE cable to the disk drive. Make sure this cable is proper seated. It should be a solid fit. The power connections (red and black wires on the side of the cable) are to the left of the drive.

The completed system is now ready for software (Fig. 14). I recommend running it open for the initial software installation so you can change the power and hard-disk LED connections if necessary.

Elapsed time for construction the first time is about an hour. It is possible crank these things out in half that time once you are familiar with the procedure.

File Server/Gateway Novell SUSE Linux
I installed SUSE Linux using a display, keyboard and mouse but then ran the system without any of these. I like Linux for this type of application because of the remote management services like SWAT, a Web-based management application for the Windows-compatible Samba file server.

There were no surprises with the installation. It handled both network adapters and I used fixed IP addresses for both. I enabled the DCHP server on the local network and ran Samba to provide file services. Samba was setup as a primary domain controller allowing it to handle Windows logins.

I won't go through all the other services installed but I did load the SSH (secure shell) server and a VNC (virtual network computing) server for secure remote management. The latter provides graphical remote control, letting me control the server from almost any Internet PC.

Novell's YaST (yet another setup tool) make initial configuration of most services a matter of choosing properly.

Mini-ITX System And Windows XP Professional
Windows XP Professional installed easily on the ML8000A. Additional drivers were included on the VIA installation CD. These enabled the USB support at which point things really started clicking. One of the options I need to check out is a USB camera but that will have to wait for now.

Windows XP Professional did a good job of connecting to the domain server. As with most operating system installations, they work from after the initial installation so it took quite awhile to add all the other Windows applications I use. These include the Firefox Web browser, Thunderbird e-mail program, and Microsoft Office. I decided to leave OpenOffice for the Linux installation. Then there was the antivirus software, Web editing tools, and so forth. Windows provided all the basics, such as the ability to watch DVD movies. It was a snap to use the USB connection with my Pentax Optio camera. It happens to run the Express Logic Threadx RTOS.

Multimedia Workstation And Mandrake Linux
I installed Mandrake after Windows XP because it is more amenable to dual boot support than Windows XP. The Mandrake installation went very quickly as I had left enough space on the hard disk for both operating systems.

The Mandrake installation program did a good job of recognizing the hardware on the ML8000A. I was able to connect to the file server using Samba and the gateway provided access to the Internet.

Mandrake came with more than one complete office suite plus multimedia support. Watching DVD movies was a snap. Mandrake can be made to look very similar to Windows XP but I tend to prefer a more traditional Linux layout.

The PowerPack version provides three additional CDs of application software. Luckily the hard disk had plenty of space to let me try out the latest and greatest under Mandrake Linux.

Closing Remarks
The Mini-ITX form factor has been around for awhile but it has not been until lately that the functionality of the motherboards has gotten really interesting. The PD10000 is a great platform for a variety of gateway products. It is also ideal for developers who would rather plug in hardware and customize software rather than build a custom hardware.

The form factor also fits into a lot of spaces that normal PCs do not. For example, a number of cases are available for automotive applications. Combine this with an optical drive and possibly an off-the-shelf LCD display and you can create all sorts of mobile vertical market solutions.

Related Links
Express Logic (Threadx RTOS)

Logic Supply (micro-ITX source)



Novell Suse




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