CPU Shack: Rare Cyrix Cx486S-40 w/ Cx487S in interposer

[CPUShack]

This is a rare early Cyrix 486 CPU with the Cx487S embedded in the interposer/adapter (since the Cx486S did not have one on die)

Very good condition - Both are dated 1993


The Cyrix 486S is essentially a Cyrix 486DLC with 2kb of L1 cache. The L1 is unique in that it offers a “Burst WriteBack” mode.

The Cx487S is indeed the 387 math-co. It’s slower than the 486DX’s setup, but this upgrade allows the M6/Cyrix FasCache to “become” a 486DX

This is the 168C version, the 168D version contained a 74F74 Dual FF SOIC on the bottom that this version lacks


$125 sticks it in your box

[dennydo]

Ill take

[H3nrik V!]

I've always found that "interposer" for an x87 to be a somewhat elegant solution

[CPUShack]

Got another one of these, same revision
1 week newer CPU

[antimattr]

I'll take it.

[black_monolith]

Is there any literature available for this CPU?
Supposedly when you attach the FPU interposer to the 486S it becomes a "486D". I just wanted to know if there is any official Cyrix document that can confirm this.

I'm also curious about the 486S2. Was that officially released? Did it also have a matching interposer? Perhaps with a clock doubled FPU...

[CPUShack]

[popo]

I would takeone if there is anymore available....

[Updated]
I found I have it, so I would like to cancel my request.