100 MHz 486 Monsters

Intro

Well, what with all the PS/2s modifications and upgrades being done out there by the enthusiast community I thought that it would be only appropriate to begin a "featured" item series.

To start it off, what a better way than to display a bit of work done by the great Peter Wendt. I say this because Peter has been a longtime contributor to the MCA scene, and has been one of the most instrumental individuals in providing detailed and accurate information regarding PS/2s to everyone who's ever participated in the newsgroup comp.sys.ibm.ps2.hardware. Here, we'll see a couple of complexes modified by Peter that are likely destined to be one-of-a-kinds...

Type 1 Upgrade

This first item is a *TRUE* 50 MHz Type 1 complex, which originally was designed to run a 486DX-50 and came as an option from IBM. There are not likely to be many samples of these units around; Peter acquired this complex sans CPU from Charles Lasitter by way of our Ardent-guy Louis Ohland. The FRU on the complex is 92F0048 and it is IBM Option item 6450757. Keep in mind that this is a Type 1 complex designed to run at 50 MHz!

Since the complex did not have the original 486DX-50 processor when it came into Peter's possession, Peter opted to install a replacement processor that would add some nice performance. This was done by installing a 486DX4-100 mounted atop a Reply Co. Interposer set to 2X clocking. Not satisfied with any wimpy heatsink setups, Peter added impressive cooling to the processor by slicing a Pentium-II heatsink into two (50-50 - right in the middle) and clipped one half of it to the CPU using the original P-II brackets. Peter says that in order to "make things better (looking)" he even installed the oversized P-II cooling fan on top.

Take a gander at this impressive Type-1 complex:

Type 3 Upgrade

The other featured item in this first Unplugged page is probably the thickest processor complex I've ever seen. Peter started with a Type-3 "double-decker" board to create this high-performance monstrosity running at 100 MHz. It also uses a Reply interposer to feed the proper voltage and clocking to an Intel DX4-100 processor. This lucky complex inherited the *other* half of the Pentium-II heatsink...

(Happiness is accepting that you have a fat complex...)

Note that the bottom edge of the Reply interposer extends below the processor card itself! Peter says that thanks to the very high processor slot connector the card "just fits", although it partially rests on a crystal on the planar. Peter solved the dilema by isolating the contact point with a piece of silicon tape. :-)

With the DX4 set to 2x clocking (the Reply interposer has a jumper for 2x and 3x clocking) for 100 MHz performance, the platform registers 44 BogoMips in Linux. Very impressive.


9595 Main Page