We finally found a lame excuse to make a "media center" computer (netflix), so I decided to hack up an extra XT case to fit a modern Micro ATX type motherboard and standard ATX power supply. I figured it needed a clock, and I had an unbuilt Cathode Corner NC620B Nixie Clock kit and some end view tubes, and this looked like a great opportunity to put it to use.
This is the display portion of the clock, with the seconds digits removed. The clock kit is versatile, it can be used with end view or side view tubes, and can be used with four or six digits. In four digit form, with end view tubes, it's just a tad too large to fit in a standard half height 5.25" drive bay. But with a bit of sanding on the ends of the boards, it fits a full height bay just fine. Fortunately the XT has two full height drive bays...the computer originally had a single full height 5.25" floppy drive, and a full height 10 MB hard drive. This particular hard drive holder is for a "modern" 3.5" drive, but it has a full height face plate, which is very convenient for this project.
This is the almost finished clock. It is mounted with standoffs from the front.
Here is the empty case, with a micro-ATX motherboard set in it to see how it fits. Not a very good fit. But I have lots of metalworking equipment, so I can fix that.
First step is to find a donor case that fits the motherboard. This is an IBM Aptiva from 1998, it came with a 350 MHz K6-2 processor. I had added a case fan when I installed a 2.4 GHz P4 in it years ago, but had problems with power supplies not fitting well, or the ones that do fit, didn't last long. This case is pop riveted together, making it easy to disassemble with a drill, to get the two vital parts--the end plate with the slots, and the tray with the motherobard mounting nuts.
This is the test fit of the Aptiva parts in the XT case, after removing the original XT card slots, and trimming the drive bay area. The shape of the cutouts in the case is completely wrong, so I decided the best solution was to cut out much of the rear of the case, and weld in a new piece of 18 gage steel to replace it. The power supply also had to be changed, and the modern supplies have the fan and plugs in different places.
Here is the new rear panel being test fit. I tacked it in with the MIG welder, then fired up the oxyacetylene torch, got out the body hammer and dolly, and hammer welded it in.
Here is is after doing some finishing work, and trimming the hole for the new power supply.
A coat of spray paint, then the Aptiva parts riveted in, and it almost looks like it was made that way...but not quite.
Before and After. The top computer is a very, very original XT from 1984. The bottom computer is the ATX version. It took a lot of work, but this old piece of steel is now ready for daily use serving up bad TV content from the internet, and displaying it on a 46" LCD TV.
The intel motherboard is from an old Gateway multimedia computer, it sports a 3 GHz Pentium 4 cpu, and half a gig of RAM. It also has an AGP video card with DVI out, and a SoundBlaster Live! audio card. A generic 54 mb wifi fills out the peripheral complement. Hard drive is (for now) a 40 GB PATA unit, and it has a new Sony SATA DVD burner. There are six USB holes on the back, so I can plug in a USB keyboard, mouse, and external hard drive. I need to find a good long range wireless keyboard/mouse setup, but the wired versions work for now. I modified a half height 5.25" floppy drive to act as the power switch and power light. The lever now actuates a push button, and the LED glows red when the computer is on.