Something that’s definitely undisputed as far as computer cases are concerned is that they used to be built like tanks back in the day. The plastic was rigid. The steel never bowed nor bent. The buttons and switches were large and in charge. And they always worked.
Standard PC tower cases today are lighter and put a large emphasis on cooling. However since the advent of multicore CPU technology the chips run a lot cooler than they used to. And the fact you can get super-small Mini-ITX format that runs at a decent clip means less time working in cramped quarters and more time building and getting the box finished.
Would it be a worthy DIY custom project to drag out a box that housed an 8088, 286, 386 or 486 and convert it to modern specs? It just might.
Bear in mind this is a project for those that are good with tools and know how to drill and carve holes in these old beasty cases. However when done you have something nostalgic, current and functional at the same time.
Best options for choosing an old case
Something with a 5 1/4" floppy drive in it
This can be converted over to an optical drive with relatively little hassle (the hardest part is getting the rails to match and finding a place to screw it down).
286 and 386 cases are your best bet here.
For those willing to put in the effort: You could make the front of the drive appear to be a 5 1/4", then flip down when the optical drive opens. It would take work but look very nostalgic.
Something not tarnished
Almost all of these cases back then were "putty" colored, and to be honest I miss them because there was just something that felt right about a computer being that color.
Unfortunately many get yellowed with age. If going for the ultra-classic look, try to find one not yellowed, else you’ll have to paint it. And to my knowledge there is no paint that can accurately replicate that putty color. You may get close but not exact.
You want late 386 and early 486 cases here.
Best options for what to load on the inside
The Mini-ITX motherboard is noted above. It’s a good choice because heat will be kept to a bare minimum, meaning that will be less holes to drill in the case for coolant fans. In some instances you may need to drill no holes because it will run cool enough. And you’ll have plenty of room to work.
You can find these on NewEgg easily, just search for mini-itx.
MicroATX is another option. It’s unknown whether full-sized ATX would fit; it depends on the case you get.
Where to find these beasty cases?
Local yard sales, flea markets and the like. Don’t bother with eBay because you’ll spend too much. You can probably pick one up for next to nothing.
If you want the "cool" case, try to score anything IBM. They just look darn good.
If one were crafty enough, one could make a nice little cottage industry out of buying and upgrading those old boxes to modern specs. A custom build PC with lights, acrylic windows, fans everywhere and the like? Some go for that and that’s fine. But an upgraded IBM PCjr to modern specs? That’s totally my thing and to my eye just looks better.
Remember: Anything "retro" sells. And this certainly would.

Classic idea Rich! I reckon there’s a terrific business opportunity here in reclaiming these old cases and selling them on stacked with modern hardware – I’d buy one!
Many years back I installed an Intel AT style pentium motherboard into an IBM 5150 case. I had to hack one of the drive cages with a dremel for board clearance issues, otherwise it was simple. Take a close look at the bottom front of most 5150 cases. Most have a black plastic strip glued over grill work that if peeled back might help with air flow. Many pre-release versions of the IBM PC were fanless. They went into production with power supply cooling fans to prevent overheating. I was never fond of the PCjr case with it’s sidecars.
I have built a couple dozen systems for people with their old case and it saves them 40.00 on a good day. I actually really enjoy doing it. They love it but you need to take pictures before and after just to give them some comfort that they didn’t get ripped off. I love the putty color as well… I could care less if it is yellowed. The old TRS-80 is a great case to mod
Omigosh, this is exactly what I was thinking of for the PCjr. case. Having seen many case mod examples at the Mini-ITX website, the PCjr. would make a perfect candidate. It’s got the 5.25″ bay for an optical drive, and the two slots beneath for memory cards/express card.
i bought a broken TRS-80 model 4 and am working on getting an AMD athalon board into it… i actually found a 12 inch color CRT to replace the old screen, and so far the only challenge is getting a keyboard where the old one used to fit…
thanks for the help guys.. and i do love that old putty color plastic, yellowed or not…. reminds me of the first computer i ever used a 1994 macintosh centris 610