[Problem] Downgrade of ASUS P9X79 Pro BIOS

I need to do this because i need to test something i cant do with modern cap bioses..

I wanna test 1 thing that got my attention: downgrade to old .ROM bios, backup new .CAP bios in universal bios backup, which will save it as a ROM file, and then try to flash it, will it work?

The only concern i have is ME. my ME version is 8.1, as i know only 7x is compatible with .ROM bioses. but i will use me subsystem disable/etc…


Edit by Fernando: Thread title specified and customized

Identify the CAPSULE header and remove it… depending on bios type/version and OEM.

I already identified it, but will USB BIOS flashback work with .ROM files on newer .cap bioses?

And maybe ez flash

No, of course, not…
But could if, the modified ROM is to be CAPsulated again, but we still dont know what Asus system you’re talking about or your pretensions with this…care to provide at least for users you read your posts?..

Its my p9x79 pro

Earliers bioses on this board had .ROM bios files, but since bios version 2002 its .CAP

So what you’re telling us is that you want to manually downgrade using USB BFB to early .ROM files…you won’t be able to, but you may succeed using a SPI programmer.
Usually due to major changes in bios and components in it, like DXE drivers and ME FW, etc…

Okay ill get ch341a on my hands and try to do this

Will any other tools work? like AFUDOS/FPT etc?