Case Mod Massacre

July 24, 2009

Down the stairCASE MOD or How an ALSA server moved from the penthouse to the basement.

CCB on carpet

(Slightly drag a pictures to see all of it.)

Here is my newest computer. It’s a server, so that’s why there’s no console shown. I think it is so beautiful that it belongs in the sitting room. It runs apache, proftpd, and telnet servers. ALSA sound system utilities provide a complete sound recording and playback facility. Telnet allows me to control everything from any other computer. I played with this for a few days and thought others might be interested in how such an odd looking machine came into being.

All computer problems can be made easy, or even completely transparent, by spending money – but where does that end? Simple, it ends where you just ask someone else to do the job for you. If you have to spend a lot of money on computers then you don’t understand the concept. What I’m trying to say here, is that this machine has cost two bucks so far and that is a very important aspect. The hardware may be very limited by some people’s standards – but it is still very powerful. For those that want to know, here is the rundown:

MB: ASUS P4S333-M
CPU: Intel Pentium 4 478 1.6GHz /512cache
RAM: 512MB DDR
HDD: WD 8.4GB
SOUND: Pre AC97 SB128 w/ES1370 Ensoniq chip

Yes, the HDD is small, but plenty big enough for a full Ubuntu Linux install with LAMP, which on this machine took 537MB. I partitioned it with 6GB root, 1GB swap, and 1.4GB /home. When everything proves itself, I will add a 500GB drive as a /home. Yes, I know that I will probably have to pay for that.

To make the sound system more reliable, I set the audio priorities to rtprio 90 and a nice of -10. This can be set in the /etc/security/limits.conf file. I also compiled the ALSA system from fresh sources. All that stuff can be found on the net so I won’t get into more details now. To me the important piece of hardware here is the sound card. I am looking forward to exploring the ES1370 which supposedly doesn’t have the automatic resampling of the 1371 and later chips that was introduced by the implementation of AC97.

I love the ALSA sound system. I can record, play, and set mixer controls from the command line and from any computer on the network. Isn’t that cool? To complete the concept of remote operation, I set the BIOS to wake-on-lan and installed a little piece of software to make that work in Linux. Now I can also turn the box on and off from anywhere. Anyway, this posting is supposed to be about a case mod, so here’s the story:

The “situation” started with me getting a micro ATX mainboard which wouldn’t fit any of the old cases that I had. Really, all I wanted was to use it, so I was almost ready to just pile the parts together. Finally, I decided to use any kind of holder to fasten the major parts together in one clump – à la “system unit”. There was a largish tower case destined for the dump and it occurred to me that a piece of it would tie together the PS and a drive bay. All I had to do was bolt the MB to one side. It turns out that the case was exactly as wide as the MB so here is how I did it.

case in half

I cut the case in half using my skill saw which turned out to be a quick and easy procedure. I used a thin abrasive blade and the edges turned out fairly neat and only required a bit of dressing.

piece for bottom

The side was riveted in, so I drilled out the rivets on the extra piece which was then used as the bottom for the half that I wanted. It just took four pop rivets to install it.

I also drilled out the standoffs and used them in the new pattern which I had to mark and drill. I just used 8-32 bolts from the hardware store. I was prepared to use any kind of spacer or fastener since it’s difficult to get the real thing around here, but I was lucky that things worked out easily.

mainboard installed

Here we have the PS, drive bays, and MB all mounted. The arrangement turned out to be pretty practical since there was no plan to use any cards. Unfortunately, that turned out to be a problem.

The on-board sound chip is a SI7012 by Silicon Integrated Systems and they don’t use adequate filtering on the DAC and none on the record ADC side, making the chip useless for audio. That meant that I had to add a PCI sound card – and that, in turn, meant that I needed a bracket to hold it in. I had not held in the video card while testing, but a permanent installation needed some rigidity.

bracket detail

I played with the idea of using a piece of 1/2″ angle aluminum from side to side, but finally settled on the bracket you see here. It is made from a piece of 3/16″ by 2″ aluminum and just bent in the vice. I had to drill and tap the case holes, and also tap the two holes for the cards in the bracket. I decided to make it able to accommodate two cards since it needed some width for stability anyway, and expandability is always a good idea. The extra space is over the AGP slot, but I could move the bracket to the right fairly easily if I wanted to use another PCI slot. As you can see, things are pretty tight, and the RAM is stuck way in the back. It is, however, quite easy to get your hand in there.

cutouts

On the bottom right you can see the slot on the back which was cut in half. This is half the slot which was originally for the ports. Now it turns out to be handy for installing the ram. One can just get a couple of fingers in there to operate the levers and push the sticks down. What luck!

On the left side panel you can see the drive connectors. These would have been difficult to install without a considerable amount of swearing, so I cut that little window. That was a simple solution and makes is a dream to install or change cables.

front view

The optical is an LG R/W drive, but if I find another use for it, I might replace that with a read only drive. It was just handy.

The HDD was put in the FD slot. That might be a bad idea since there is perhaps limited cooling with its metal enclosure. I don’t expect the drive to get hammered, but it would be easy to modify the holder for better cooling. The other full width slots are available for expansion. This is where I plan to put a larger capacity HDD for serious storage.

power on

Here it is turned on. I love the yellow light on the blue background. Very Swedish!

Actually, I should say something about the blue face plate. I needed a place for a light and a switch. Some existing holes in the case were in a suitable location.

The problem is that I had to find some relatively neat way of holding the parts in there. I took a piece of blue acrylic and drilled it with minimal sized holes and then just used a couple of dabs on the back with the good ol’ glue gun. The hole for the switch is recessed from the front to provide protection from accidental operation. Both the light and the switch are those typical pre-wired ones that you rip out of old cases.

That little face plate took a significant amount of work compared to the whole project, but was absolutely necessary to make things complete.

on table

Well, it looks great in the sitting room, but it’s probably handier on my regular stack of computers by my computer chair downstairs. So I set it up there and proceeded with my plans for server heaven and other coolness.

Big mistake! Luck had been with me despite minimal planning. Now there was a serious problem – the CPU fan was unbearably loud next to my ear. For a machine which was supposed to play and record sound as a major part of it’s duties, this would simply not do.

Closing the box was not an option. Nor was buying a quiet fan – or buying anything, for that matter. This was supposed to be a use-what-you-have project. What was I to do?

It took a bit of thinking – and one more hole to drill. Now the machine is going down one more storey. To run the wires, I drilled a hole in the floor by my chair and stuck the unit in the basement. Project completed.

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2 Responses to “Case Mod Massacre”

  1. Tandyman100 said

    YES! Hot glue will forever get for the win! Nice build, very well documented. I especially like the final “oops, too loud. Time for hole-in-floor!” fiasco.

  2. voxigo said

    There are two kinds of people. Those that use hot glue, and those that use gaffer tape.

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