Mega-ITX: Construction (Part 3)

As I said earlier, the case was gutted and several of the plastic parts of the case were removed. I wanted to also reduce the noise coming from this system, electrical noise that is, due partly because we have a HAM operator living next door but also to reduce interference with any of my other equipment. Hence some of the original metal shielding has been left in place.

The next step was to open part of the back of the casing up to allow access to the ports on the motherboard. I decided at this point to make a hole large enough to allow the standard metal bracket to be mounted.

Initially I was going to sit the motherboard level. However this then creates a major problem. That is that the RAM sits too high to allow for the DVD-ROM to fit in the case and use the original CD opening. I could have moved the DVD-ROM tray and created another opening, but then what's the point in modding something like this if you are not going to use the original characteristics? At this point, the only real alternative was to sit the motherboard in at an angle, which presents another minor problem that I will discuss later. Two holes were drilled through the case to allow the motherboard to be secured. To stop any shorting, a sheet of plastic was placed between the metal on the casing and the motherboard. The same problem is presented with the PSU board, and so the same solution was applied.

At the start of this project, I thought a motherboard, 17cm x17cm and a case as big as the MEGA-CD would have plenty of room. At this stage it was becoming apparent that I may be wrong. I attached the PSU cable to the motherboard, which instantly showed how tight it was going to get.

Now comes the fun, fitting the hard disk and DVD-ROM. The hard disk used was a 40GB 2.5" laptop, so was more than small enough to fit in the case, but where. Lets just side step a minute. I am using a laptop hard disk as they are virtually silent, draw less power and are smaller. I am also using a slim line (laptop) DVD-ROM drive. Again this is because a full sized drive simply would not fit in the case. If I had used a 3.5" or full CD/DVD drive I would also have required a larger PSU, which would then mean a larger case and more noise, in turn making the objective of this project unreachable.

Anyway, to mount the hard disk and DVD-ROM drive a employed the help of my father (Paul Young) to make me a bracket out of stainless steel. This allowed the DVD-ROM drive to be attached by screws on one side and a shelf on the other. The hard disk is attached via four screws from underneath.

Now the power and reset switches are required. Since the original MEGA-CD was controlled via an attached MEGA-DRIVE, it did not have any switches. Not wanting to damage the look of the front, I mounted two switches, donated by my brother (Mark Young), on the rear of the machine.

Next comes the LEDs to indicate power and hard drive activity. The front bezel has a position for two LEDs to be attached. To keep to the original colour scheme, the power LED is green and the hard disk / DVD-ROM activity LED is red. These are then connected to the motherboard in the usual way.

Almost there. Most of my work is now sent either via email or on a pen drive. I did not want to keep fiddling around at the back of the machine to find USB ports, so decided to mount two extra USB ports of the part of the case that rises on one side. This originally was used to connect to the MEGA-DRIVE. I required a special cable to convert the mini header to a normal USB (0.1") connector. The USB connectors themselves required significant modification, trimming, etc. to get them to fit.