486DX2-66 worth keeping?

[Th3_uN1Qu3]

Re: 486DX2-66 worth keeping?

Wouldn't that be 250MHz? The 200MMX had a 3x multiplier. 83.3*3 = ~250.

Did you actually have a 233MMX?

The MMXs had unlocked multi. If you had a board that could set multipliers manually you could run a 3x multi chip at 3.5x. I still have screenshots somewhere to prove it. The 233MMX i had would not run past 266.

With a peltier on it cooling it down, along with a giant heatsink, it would run at 300MHz on a 100MHz bus! The real surprising thing was that, at that speed, it was faster than the K6-2 that replaced it!

You got lucky, few boards could run at 100MHz stable. Then again, my Asus P55T2P4 was a regular Socket 7 not Super Socket 7. It had jumper settings for 100MHz but it would not even POST at that frequency.

[acstech]

Re: 486DX2-66 worth keeping?

You must have been the lucky one then. All the ones I've seen have been locked. Believe me, I tried setting mine to 3.5x more than once, and always it just ran 3x like it had always done.

Did yours have the large ceramic case, or was it the black one with the metal IHS?

Edit: Maybe the unlocked ones were a regional thing? Meaning, those sold in the US market might have been locked, and those elsewhere might not have been.

Edit2: Mine wouldn't run past 250MHz without the peltier cooling it down first. It wouldn't even post unless it was very cold. How cold I don't know, but I do know that it was starting to frost before I shut it down. Once it started it was perfectly stable though.

[PCBONEZ]

Re: 486DX2-66 worth keeping?

The MMX's were locked. (Except -possibly- for QS which were very rare.)
The motherboards that used them allowed changing the FSB.
.

[weirdlookinguy]

Re: 486DX2-66 worth keeping?

Ah man guys, I ended up having to throw the thing away to make room for a G4 Power Mac and LCD that I found. Now I'm reading through this thread and I think I may have made a mistake. Oh well, it's gone now. At least I tinkered with it for a bit and took pictures.

[Topcat]

Re: 486DX2-66 worth keeping?

The MMX's were locked. (Except -possibly- for QS which were very rare.)
The motherboards that used them allowed changing the FSB.
.

All of mine were always locked. My 233's would run 100% rock solid stable at 266/75. They would POST 290/83, but were never stable.

I have some P3 engineering samples and some 604 xeon engineering samples that are on the fun side though.

[PCBONEZ]

Re: 486DX2-66 worth keeping?

As I recall 'unlocked' didn't show up until P2.
Those still carried the 'MMX' tag so that's probably where the confusion comes from.
.
I have some Xeon socket 771 QS around.
Don't actually use them though.
.

[Scenic]

Re: 486DX2-66 worth keeping?

I've got an embedded Pentium MMX 300MHz somewhere (Tillamook core in normal socket 7 package)

Always wanted to try and OC that thing to see how it would keep up with a K6-II or 3 but never got around to do it. I do have a bunch of actually quite nice Tekram (remember them?) Super Socket 7 boards to play with..

[PCBONEZ]

Re: 486DX2-66 worth keeping?

YES I remember TekRam.
They made pretty good boards.
I used to buy them in 10 packs for resale when I had the store going on.
They were good sellers too.
.

[lti]

Re: 486DX2-66 worth keeping?

I have a working Pentium MMX 200 and a Cyrix MII-333GP (the 83MHz FSB version). They both perform the same at their stock clock speed. I never tried overclocking them. The Pentium runs warm enough at its stock clock speed. The Cyrix came from a Compaq, and (of course) they decided to run it on a motherboard with a chipset that was only designed for up to a 75MHz FSB. That board was picky about RAM (using RAM it didn't like gave typical "bad caps" symptoms), but I am still using it with a K6-2 and 128MB of RAM that only this computer likes (the stick only has four chips, so my only other boards that use SDRAM only detect 64MB).

As for really old computers, my dad has an AT clone that has been sitting in the basement untouched for the past 18 years.

[Hemingray]

Re: 486DX2-66 worth keeping?

Random thought, one may be able to load up a small Linux distro (DSL, Puppy, etc) and get some use out of such a beast.

[bluto]

Re: 486DX2-66 worth keeping?

While possible, there is not much practical use for a linux box of such lowly specs these days. Believe me, I had a 486 setup as a linux nat router for a time. But that time was over 10 years ago. Anything less than a P3 now days is just wasting your time and electricity trying to accomplish anything useful with linux. The occasional DOS game is about all a 486 is good for in 2012.

[ratdude747]

Re: 486DX2-66 worth keeping?

the only graphical distro that will run on a 486 is DSL.

[Clydeuk]

Re: 486DX2-66 worth keeping?

I still have an Amstrad 286 machine somewhere, it was my first PC. I ran MS-DOS 3.3 and Windows 3.0 on it. I remember enjoying playing Elite on it (it had built in VGA graphics and looked awesome compared to the PC/XT's with CGA). I know I should junk it (the CRT monitor got thrown years ago after the CRT wore out), I just can't part with it.

In the late 90's I remember bunging in my old 28.8 ISA modem and using some DOS software managed to get on the internet and send an email to a friend.

[hardwareguy]

Re: 486DX2-66 worth keeping?

See that extra row of pins around your 486? That's for a P24T...aka Pentium Overdrive Processor! An 83MHz PODP will eat that DX/4 alive when the FPU is loaded. Performance is similar to a Socket 5 Pentium 75 due to the PODP being on a 32 bit memory bus that is partially offset with a double sized L1 cache.

A P75 will play MP3s just fine.

https://en.wikipedia.org/wiki/Pentium_OverDrive

[Agent24]

Re: 486DX2-66 worth keeping?

See that extra row of pins around your 486? That's for a P24T...aka Pentium Overdrive Processor! An 83MHz PODP will eat that DX/4 alive when the FPU is loaded. Performance is similar to a Socket 5 Pentium 75 due to the PODP being on a 32 bit memory bus that is partially offset with a double sized L1 cache.

A P75 will play MP3s just fine.

https://en.wikipedia.org/wiki/Pentium_OverDrive

Funny, that Wiki article seems to say the opposite:

When the Pentium OverDrive 83 MHz launched, significantly later than the mere 63 MHz version, it did so at $299, an exorbitant price compared to other upgrade alternatives.[2] The AMD 5x86 and Cyrix Cx5x86 processors were usually faster and were considerably cheaper[citation needed]. Even Intel's own DX4, based on an older chip architecture, was typically faster. Only on some applications, where floating point arithmetic was used, could the Pentium OverDrive outperform its predecessors.

Go AMD!!

[BigTroll]

Re: 486DX2-66 worth keeping?

First of all... I wanted to tell you about my "AWARD WINNING" Packard Bell Legend 10CD. Its got a 66mhz 486 DX2!!! was a SX2 50.

PACKARD BELL "America grew up listening to us. IT STILL DOES!" oh btw i can't do a 83mhz overdrive, requires a damn interposer in these PB450 boards.

[RJARRRPCGP]

Re: 486DX2-66 worth keeping?

I have a working Pentium MMX 200 and a Cyrix MII-333GP (the 83MHz FSB version). They both perform the same at their stock clock speed. I never tried overclocking them. The Pentium runs warm enough at its stock clock speed. The Cyrix came from a Compaq, and (of course) they decided to run it on a motherboard with a chipset that was only designed for up to a 75MHz FSB. That board was picky about RAM (using RAM it didn't like gave typical "bad caps" symptoms)

The RAM symptoms sound more like today's boards. Pre-2000 or at least pre-2003 boards actually seemed less picky, I dunno why...

It sounds highly likely that the contact with the springs were poor... This seems more common with boards made in this century!

On recent boards, it seems I have to reseat the RAM a gazillion times before it will even boot, when I installed a known good Corsair 1 GB DDR 2 SDRAM stick on to the eMachines T3516A Celeron D 352 box, which only had 512 MB of RAM and only 384 MB for Windows!
No wonder why even XP lagged! Much less a normal Windows 7 being tolerable! You could forget about running a default Windows 7 reasonably!

Maybe 7 would work a little better than XP for videos with the Corsair 1 GB DDR 2 SDRAM stick...

[Elysarian]

Re: 486DX2-66 worth keeping?

Good lord... I had one of those BITD...

Gave it to my dad when I upgraded to a Pentium MMX, if I recall it ran well enough with win95OSR2 (I think there was 16MB ram in mine and I filled those empty DIL sockets with cache ram I salvaged off another (dead) 486 board.

Very clean insides for a machine of that vintage (reminds me of a box I saw recently at a clients site, no idea what's in there but it's of the same vintage as the OP's machine and looks like it's never been booted up!)