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IBM PC AT 286 to 486DX-2 or DX-4 Upgrade

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jacobtohahn

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I have an IBM PC AT 5170 with a 6Mhz 80286. I saw somewhere that someone had upgraded an AT with a 486DX-4. Is there a card or socket upgrade of some sort that I could get to do so? If anyone has one I’d be glad to buy it.
 
Pull the motherboard and put in a 486 AT board and you'll be good to go. There is no drop in upgrade that I am aware of. There were some drop in 386 board/cpus that were made to fit in the AT case, but you'd still be replacing most of the innards.
 
lutiana said:
Pull the motherboard and put in a 486 AT board and you'll be good to go. There is no drop in upgrade that I am aware of. There were some drop in 386 board/cpus that were made to fit in the AT case, but you'd still be replacing most of the innards.
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Extend-It Technologies made a "Make It 486" Processor Upgrade for 286's. I had one. They also bade a 16-bit ISA Memory Expansion card that would fit 16 megs across 4 SIMM's. Great pieces of technology, too bad I didn't keep them.
 
lutiana said:
Pull the motherboard and put in a 486 AT board and you'll be good to go. There is no drop in upgrade that I am aware of. There were some drop in 386 board/cpus that were made to fit in the AT case, but you'd still be replacing most of the innards.
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Link to a motherboard that will fit in a 5170? All of them are ATX or for PS/1 systems.
 
jacobtohahn said:
Link to a motherboard that will fit in a 5170? All of them are ATX or for PS/1 systems.
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Just look for an AT 486 board on Ebay, most of them should fit in that case fine. I mean, that board is the originator of the AT standard :D
 
I think the important thing to note is that if you decide to retain the original 5170 planar and "upgrade" it with an add-in 80486 card, it's entirely possible that (a) performance will be lower than a comparable 486 planar and (b) it will suffer compatibility issues.

Just my .02.
 
Chuck(G) said:
I think the important thing to note is that if you decide to retain the original 5170 planar and "upgrade" it with an add-in 80486 card, it's entirely possible that (a) performance will be lower than a comparable 486 planar and (b) it will suffer compatibility issues.

Just my .02.
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I’ve heard the same thing. Planning on replacing the board.
 
I have never seen a dingus to go from a 286 directly to a 168-pin 486, but I have seen modules that let you go from a 286 to a 386DX or 486DLC. In theory if you could remove the CPU, you could upgrade it further with something like a Cyrix DRx2 or a SXL2. There are also adapters that let you go from a 386 to a 486, but it's likely that using two of these adapters together wouldn't work, and it would be quite bulky.

The best direct upgrade I've seen is the Evergreen modules that upgrade you to a 486SLC2-66, but I haven't been 100% successful getting mine to work properly.

A board replacement is of course way easier, but also not nearly as fun.
 
At this point I'm not sure if there's any reason to upgrade a PC AT with a 486 system board. You might as well just pick up a 486 system and leave the AT in its original configuration. If you don't want a 286 system at all you could probably trade the whole thing to someone for a 486 system.

The 'upgraded' system won't work as well as a real 486 system, and its value as a 'vintage' or 'collector' computer will be diminished. I'm not sure why anyone would want to go down this path today. I could see doing this in 1994 maybe, but not today.
 
The IBM 5170 case is AT-style, this means that any AT or Baby-AT motherboard can fit into the case. Even some rare AT Socket 478 motherboards, such as Commate P4XB. But after the upgrade the IBM PC AT 5170 will no longer be an IBM 5170, it will be a some AT-compatible computer in the old IBM case.
 
Fire-Flare said:
What if they like the way the AT looks? That's why I put a Super Socket 7 board in my PC XT case.
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That's about the only reason I can see to do it. In that case you're better off doing this with a dead system, rather than parting out a good one.

I used to do this kind of thing myself, cobbling systems together from whatever parts I could get my hands on, but this was decades ago when these things were relatively new and readily available. Now that they are becoming "vintage" we are less and less able with each passing year to justify breaking up a working system, especially if it's becoming rare.

There was a time when it could be considered an "upgrade" to replace your AT system board because you were taking a system with very little value and at least making it useful for what were then considered "modern" applications. But today I think we're at the point where an IBM AT case with a clone motherboard is worth less to collectors compared to a still-intact IBM AT. In other words, today such an "upgrade" is actually a "downgrade".
 
kgober said:
But today I think we're at the point where an IBM AT case with a clone motherboard is worth less to collectors compared to a still-intact IBM AT. In other words, today such an "upgrade" is actually a "downgrade".
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I completely agree with this, but ....

The 'upgraded' system won't work as well as a real 486 system, and its value as a 'vintage' or 'collector' computer will be diminished. I'm not sure why anyone would want to go down this path today. I could see doing this in 1994 maybe, but not today.
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An original system with an upgrade card is something else. I agree with you that it won't work as well but it still has some historical value. I have a 286 card that you stick in an ISA slot and then you have to replace the 8088 with a connector that on its turn is connected to this upgrade board with a band cable. Weird thing: the PC becomes twice (?) as fast but the card has only 512 KB of RAM on board, not expandable, so I ran into memory shortage some times. And sometimes a program wouldn't even work. But people who saw the system considered it as very cool!
 
jacobtohahn said:
Link to a motherboard that will fit in a 5170? All of them are ATX or for PS/1 systems.
Click to expand...

AT and Baby-AT mainboards were available until the Super Socket 7 (AMD K6-2) and even Slot 1 (Pentium II) era, they even had AGP V1 slot. On the other side, there were never ATX mainboards for 80486, ATX started with Socket 7 (Pentium MMX, AMD K6/K6, Cyrix 5x86) era. An 5170 with AMD K6-2-400 should be possible.
 
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