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How Difficult Would It Be To Make an Interposer That Routes All Vcc Through a Variable Voltage Regulator?

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First post, by Paralel

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After looking around enough I finally found some pinouts and other information on IBM's 486SLC3 chips. Apparently they conform to 386sx pinouts, except instead of having a Vcc of 5V or 3.3V, they actually use a variable voltage that can change from between 3.3V to 4.1V, so they use a voltage regulator, LT1085TC, that can provide variable voltage as needed.

How Difficult Would It Be To Make an Interposer That Routes All Vcc Through a Variable Voltage Regulator?

I also noticed that the board the processor is on has the part below on it.

Can anyone tell me what it does? I tried to look up the part number with no luck.

I figure if a variable voltage interposer can be made, this would allow the most powerful chips that are directly 386SX compatible to be used in any machine.

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Reply 1 of 4, by keropi

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That part u mention is a 74F08 , see some 74LS08 datasheet to know more , F is the faster version of it

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Reply 2 of 4, by Paralel

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Ah, okay, doesn't seem to be important then. It is likely related to the 387sx that can also be on the board, since it sits between the two. So, the interposer would just need to work by adjusting the voltage. Shouldnt be too bad? I guess?

Reply 3 of 4, by gdjacobs

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keropi wrote:

That part u mention is a 74F08 , see some 74LS08 datasheet to know more , F is the faster version of it

74F is sorta Fairchild's equivalent to the 74AS series from TI. It's a little faster but with a little more power consumption than the 74LS series.

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Reply 4 of 4, by Paralel

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Looks like I found my answer in one nice, well written document by IBM:

http://datasheets.chipdb.org/IBM/x86/486/40011.PDF

Turns out, while not easy, its not exactly difficult either. Def. way more work than I'd want to undertake.

If anyone else is interested in doing it, let me know.

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