What programs do you intend to run with this machine? What operating system?

Are you interested in enabling the special performance enhancement features of this CPU?

You might want to consider adding a fan to the heatsink. I recall these getting awfully hot without a fan.

You may also want to consider replacing one of the 5.25" with a 3.5" drive.

@feipoa

I generally plan to use this computer for games from around 1990-1996, and thus I don't think I need to enable any extra features of this CPU. Actually, I want to keep it as much 486 as possible.

You may ask why then I don't use a regular 486DX2 or 486DX4 - well, I collect some of them, but I just couldn't resist this blue IBM.

I will be checking on the temperatures - to see if it really runs hot (as I have tested it without the case, it was running quite cool to my taste). I surely would need to get some fan that would not damage the heatsing in any way (I've seen many IBM 5x86C with damaged heatsinks caused by fan screws).

Quite interestingly, this CPU seems tu run much more stable on ATC-1425B than on my 4DPS. I just couldn't boot the computer with L2 writeback enabled, while in case of this mobo it's not a problem anymore, and neither burst-mode is.

The only dissapointment for now is that for reasons unknown I can't get IDE led work with this adapter in this mobo. It worked just fine with 4DPS. The led itself was tested and is OK.

I will surely get 1.44 FFD. Just need to get some bay adapter.

***

BTW - does anybody have any experience with refinishing case plastic faceplates? There are some relatively noticable scratches on the sides of my faceplate and I would like remove them or make them less visible. Some filler/sanding?

I have noticed that the 3.45 V setting on the 4DPS can be set very low. Mine measured 3.29 V, which is too low for most Cyrix/IBM 5x86 chips. You can modify the VRM on the 4DPS to allow for variable output voltage. This is what I did.

You could use the special IBM features to slow down the CPU if you wish.

I supposed this could be some problem with CPU voltage.

When it comes to slowing things down, first I'll try playing with it for a while - I noticed that hitting turbo button slows it down drastically (Speedsys), so maybe that will be enough. If not, I will definatelly try extra settings, or maybe switch to regular i486 DX2 😀

Things are getting more and more crazy with this build. I pretty much liked the idea of putting 3dfx into this 286 case and today I did. just got my Diamond Monster 3d. The card I couldn't get when I was stuck with my 486sx 33 (4mb ram) back in mid 90s (and wanted it so badly).

Too bad I still don't have an interconnect cable to give it a try 😀

My only concern is whether my 150w psu will handle all that stuff.

> Too bad I still don't have an interconnect cable to give it a try 😀

You can do the switch manually.

I really like this build that you are doing, and I am a bit..... No... Really envious on you'r case. 🤣
I simply love cases like this, yet I have never owned one in my entire life.
Hope to find one my self, at a reasonable price here in Denmark.

I love them, too. And the thing I love moste about it is the power switch located directly on the PSU (on the side). Simple, yet magical, as it reminds me my first pc. Quick access to internals is also a pretty cool feature.

When I notice something comparable on my local 'craigslist', will let you know.

What I generally love about all this hardware is the fact that... it does not age anymore 😀