Old school overclock

[myststix]

Ok oldies, I got a good one for you.

I am trying to overclock a 486 computer.

I understand you can raise the front side bus by switching crystals.

If that works, I might try to overclock my old IBM 5150.

Totally serious about this. I collect these dinosaurs!

 

[tech9]

Don't worry about heat issues, my 486 didn't even have a heatsink.

 

[Ben333]

can always stick an old CPU or video card sink on it. Yea, swap the OSC with a better one.

 

[Zuzzz]

It overclocks with jumpers. That diagram SHOULD be listed on the motherboard somewhere. The crystal will be either a 25/50, 33/66 or 4/80. The multiplier is more or less unlocked. Got anything most specific as far as the currect clock speed?

Z

 

[w2richwood]

oh man the good old jumper days lol
Rich

 

[Niku-Sama]

heh, this isnt even jumpers, i picked up an AGP equiped socket 7 AT board today.
this type of stuff is cool

 

[myststix]

Got anything most specific as far as the currect clock speed?

I got an AMD 5x86-133 @ 160Mhz (40FSB x 4)

However, I think I can go faster.

I want to do 50x4=200Mhz.

Does anyone know a place that still sells overclocking crystals for these old units?

As far as heat, I got a peltier unit to cool it.

"Must ....go....faster...."

 

[Zuzzz]

Is the clock crystal on it a 40mHz or an 80? If its an 80 you need to find the divider jumper for the crystal. As I recall you had to set that as well as others. Wish I knew what board it had. If its a supersocket7 you may not need the crystal. It may allow you control in the BIOS.

Z

You MIGHT find that part here:::
http://www.nwequipmentsales.com/Vintage PC Parts.htm

 

[myststix]

This is an old 486 board, I'll check the crystal timer and post it here. It has multiplers for 2 , 3, and 4...and bus speed right now at 25, 33, 40 and 50. It's at 50 right now.

 

[Zuzzz]

If it is the 50mHz oscillator chip youll want to get the 66mHz. If you got the FSB to 50 wouldnt that be 50x4=200?. I'll suggest find the jumper for the divider on the motherboard. even though it is 50Mhz there is a jumper that is dividing it. Again it my be printed on the board.

Z

 

[~(o)-(0)~]

dude...you're awesome!!

can't help u on the OC though, when i OCd my 486s it was pretty much exclusively with the jumpers on the board. I got a 40mhz up to 120 once, but it melted the socket within minutes...was pretty amazing. The chip and board still worked fine after, but I got a huge blister pulling the cpu out of the board

 

[myststix]

Going for 200Mhz.

dude...you're awesome!!

can't help u on the OC though, when i OCd my 486s it was pretty much exclusively with the jumpers on the board. I got a 40mhz up to 120 once, but it melted the socket within minutes...was pretty amazing. The chip and board still worked fine after, but I got a huge blister pulling the cpu out of the board

Going for 200Mhz this weekend...

 

[Zuzzz]

Let us know how it goes...

Z

 

[myststix]

Let us know how it goes...

Z

I'll post a video!