First post, by Kiteless
- Rank
- Newbie
Greetings, I searched around on the forums and wasn't able to find the answer so hopefully someone can point me at a thread that already covered this exact topic. I recently got my hands on an elusive (for me anyway, and not ebay prices) 386. This one is a 386 DX33. With all the old hardware and PSU it actually boots up fine. I plan on doing a "resto-mod" do it. Swap all caps, especially tantalums, replace Dallas Clock with a modern solution and use a new ATX PSU.
So here is my question: I read that modern PSU's have a weak if not totally nonexistent -5v rail and that AT PSU's are much stronger on their 12v side than the 5V side as older PC's are more 12v dependent (or maybe I have that backwards). As I understand it a weak or missing -5v on a modern ATX PSU is generally not a problem except certain ISA add on cards like a sound card need -5v to work. 1. Is this all true? Are these things I need to be keeping an eye out for? 2. Can anyone tell me just how powerful a particular rail should be to comfortably run a 386 DX33 and also a 486 DX4 100? 3. If -5v is critical what is the minimum current I should be looking for there?
I have a new old stock AT PSU powering my 486 build and it's been working absolutely fine but it's still like 20-25+ years old so I want to replace that PSU with something modern and solid. Some of these computers I'm planning on keeping till they crumble into dust and fine with buying like a really nice Seasonic for them. Any help/guidance would be super helpful. I've had a heck of a time tracking down more details on this. Below is the adapter I purchased to do this. Thanks all!
YouTube channel
https://www.youtube.com/channel/UCTfnRX4AWhbYJuguUcEff-g
Main Systems
NuXT
IBM 5140
486 DX4 100Mhz (Mainly DOS)
AMD K6-2 500Mhz (Mainly DOS)
AMD Athlon 700Mhz 9700 Pro (Win 98)
Pentium D 3Ghz 4670 AGP 8x (Win XP)