I would concur: The 386sx was just 16 bit. The 387sx was for that 16 bit processor. The 486sx was no math co-processor, and the 487 was a whole 486 DX, i.e. the

I would concur: The 386sx was just 16 bit. The 387sx was for that 16 bit processor. The 486sx was no math co-processor, and the 487 was a whole 486 DX, i.e. the vacancy slot, brought to you by Intel Marketing.