Personally I'd keep this system and bought a complete 486 - already prebuilt or in parts if you like to play with the hardware 😉

Yeah that 286 looks too cool to be harmed 🙁

By the way, there's a battery on the motherboard nearby the keyboard connector. Remove it immediately before it leaks !

As for parts, search locally, you won't find any good deals on ebay except if you're lucky

That thing is adorable. Is that the original case for this motherboard? The case almost looks like it originally housed a 486 DX2-66.

Absolutely lovely PC. Don't mess with it and just build separate 486 machine.

I second. This is a lovely case and a lovely Cyrix FPU (that I envy 😁). I'd keep the config as it is now.

(And if you happen to know how to set this Hedaka board to WS0 operation, please let me know. It looks pretty much like mine.)

dada wrote:

I'm thinking I'll need to replace every card inside too since I think these are ISA slots and good 486 boards probably only take PCI, right?

Early 486 boards were ISA-only.
Then there were the VLB boards, where you can use both ISA and VLB cards.
Late 486 boards would have ISA and PCI (stay away from the ones that offer both PCI and VLB, they are generally very buggy).

So most 486 boards will have ISA slots. But it is recommended to replace at least the video card with a localbus one (be it VLB or PCI, depending on what board you get), because the performance difference is quite relevant.

Late 486 boards may have the multi-IO integrated on the board, so you won't need a separate controller for floppy/HDD etc. Otherwise, you could get a localbus one for that as well, but performance-wise it is far less relevant than a videocard.

For other stuff, such as a sound card, it's not relevant either. ISA cards are probably preferred over PCI ones for better backward compatibility.

Get VLB. While VLB had it's issues, PCI implementations on the 486 platform was often as bad or worse. VLB's issues were mostly mechanical. The cards were massive, and the connectors were even worse (imagine putting a full 16-bit ISA connector and PCI connector back to back.), and on cheaper boards could have constant connection issues, but when they do work, they work well and fast.

I honestly would keep the 286 system. 80286 systems complete with a 287 is worth WAY WAY WAY more than a 486 machine. If you are hankering for a case for a 486, get a cheapie Newegg ATX case and just leave the IO shield out. It's better than cannibalizing such a cool 286.

oh oh that machine is beautiful. I agree also with just building a new 486 setup on the side 😎

if you really must, you won't have any trouble swapping a 486 baby AT board into that box, just make sure you get it setup exactly how you want it (jumpers, cache, etc) precisely and test it before you put it in there, otherwise something as small as a cache upgrade turns into a full teardown nightmare !

All you'll really need is a socket 3 board (look for one with a cr2032 if you want this to be painless). If you go VLB get a vlb IDE controller and a vlb graphics card. You might end up needing some 70 pin simms too. Besides that everything else should be fine in there.

OK, I have to say that you guys convinced me not to tear down and modify this 286. Truth be told, I wasn't sure about whether or not to convert it, because it is a very nice device. Got it a while back, I installed a CD drive and radio card (Spase PCRADIO, although I don't know where the antenna is) and I'm pretty sure there aren't many 286es with that kind of cool stuff. So yeah, maybe I should just keep it intact and figure out something else instead.

I'll probably get rid of (sell to another retro fan) one of my other computers to make space. I'll probably just scour local ads for old computers considering how expensive the hardware is on e.g. eBay...

Thanks for offering your thoughts. 😀

Deksor wrote:

By the way, there's a battery on the motherboard nearby the keyboard connector. Remove it immediately before it leaks !

You're right, I'll have to remove that... thanks for the heads up.

Its hard to tell from your battery picture but it looks like it might of leaked already I thought I saw some green corrosion near the battery.

I have that very same case housing an UMC U5SX@40Mhz on a Chicony CH-498B mainboard (486 Socket 2 MB with an UMC 498F VLB chipset). Previously I had a 486 DX2 on that board but I swapped it with the U5SX and I still have not updated the LED display accordingly. IMHO this case is more appropiate for a late 386 or pre-PCI 486. For a 286 I really prefer desktop cases (if you can find a slim one, much better). Here is a pic of my 286 running:

dada wrote:

The motherboard seems to be around 33x21cm. I'm thinking I'll need to replace every card inside too since I think these are ISA slots and good 486 boards probably only take PCI, right?

Regarding this observation - most motherboards still included at least a few ISA slots right up to the Athlon and Pentium 3 era. Some Socket A (Athlon/AthlonXP) had them too, though Pentium 4 machines usually didn't. (This is similar to how old-school PCI persisted in some capacity right up to at least Haswell/Broadwell, and I think there are some Skylake boards that have it. AFAIK no Kaby Lake or Ryzen boards do, however.)

Also, for a DOS machine - ISA all day, every day for sound cards. There do exist some PCI sound cards that'll work, but if you have an ISA slot and you intend to run DOS, get an ISA sound card and save a lot of aggravation. If you can't find everyone's favorite Creative cards, or don't want to pay the premium, look for anything with an ESS1868 or ESS1869.

BeginnerGuy's advice is solid, too. If the board has onboard IO, it's going to be on the fast bus (VLB or PCI, depending on what the board has), generally speaking. PCI graphics cards are typically fine for DOS/Win95, too - especially Cirrus, S3, ATI Mach64/Rage Pro or Tseng. (Trident sucks and Matrox, while fast, has occasional VESA graphics glitches especially in Commander Keen games, but there were others with problems.)