Unknown beautiful IBM chip on a 486 mobo - info wanted.

[slava]

This a 486DX2-66 IBM motherboard. The greenish chip packaged as if it was a PowerPC processor is really odd looking. Anyone can explain what it is?
That double slot with large number of pins on top of the S3 graphic chip is also interesting, never seen any of them before. What was it used for?

[CPUShack]

Wow, nice looking chip, its the same package as IBM used for PowerPC CPUs.

Maybe a cache controller?

[gshv]

It can be SynchroStream Controller. From PS/2 FAQ:

"SynchroStream(TM)controller which uses IBM's most advanced technology packaging to integrate 5 major chips (memory, I/O, DMA controllers, FIFO buffers, ECC logic) into one chip. This technology allows the high-speed interconnects and large streaming pipes that form the SynchroStream engine to provide state-of-the-art performance. The SynchroSteam controller synchronizes data traveling between major subsystems and allows it to stream in parallel, at full bandwidth, to each subsystem concurrently."

Gennadiy

[CPUShack]

a chipset in otherwords, very nice still though.

[slava]

That means I own a PS/2 motherboard? wow wow wow
Thanks for the answer.