At the end I managed to update all BIOS of my machines by using the manifacturer original zip file.
Once extracted there are various files, fun part they changed the name of the main executable that had to be run via EFI with a less obviousy one and also added a FLASH.NSH file where .NSH are the EFI equivalents of .BAT in Windows and .SH in Linux.
So here's the procedure: unzip the ZIP content and put it in a flash drive, at the startup go in BIOS settings and select "Boot EFI shell", when the boot is complete go inside the flash drive content with cd fd0 or similar command where fd0 is your flash drive. At this point I first used the utility provided to do a backup copy of the current BIOS and then ran the FLASH.NSH file, then reboot and remove the external flash drive.
Answer from user3450548 on Stack Exchange[Guide] Manual AMI UEFI BIOS Modding - BIOS Modding Guides and Problems - Win-Raid Forum
Bios Mods - The Best BIOS Update and Modification Source - AMI BIOS Unlocking Requests
How can I update my Bios?
I have an asus MB but my bios version says "American megatrends inc" do I have to download the latest version of that or of my asus board?
Can I update my motherboard's BIOS from inside Microsoft Windows (@BIOS, Live Update, etc.) or should I use the UEFI tools only?
Why does my PC restart, but the BIOS update never installs?
What if the BIOS update fails halfway through? Will it break my computer?
Videos
Circa 1993, ~17650 computers were shipped with a trojanized BIOS chip. On the 13th of November, a payload would activate and the machines would play "Happy Birthday" through the PC speaker during POST and refuse to boot.
I'm on the prowl for any model numbers or leads. Ideally, I'd like to get my hands on one of these fabled machines. Realistically, I'd like someone to film the payload or dump the BIOS. Not much info on this trojan exists on the web and I'd really like to see it in action.
EDIT: The particular machines I'm looking for have an Intel 486DX chip.
EDIT 2: After further inspecting the BIOS output in the quoted source, the machines affected used the i486SL variant of the 486DX chip.
Info copied from elsewhere:
The sticker on the trojanized BIOS chip says:
AMIBIOS
AMERICAN MEGATRENDS
486DX ISA BIOS (c) 1993
AB 3756612
The next three faulty chips (all with Flash ) had numbers (telephone report):
AB 3756271
AB 3756631
AB 3738981
The easiest way of identifying the trojan is:
- change date to 13th of November (year doesn't matter)
- reboot PC
After displaying messages simmilar to the ones below, you'll here the
tune.
Cache in 2-Bank!
33.06x2 MHz CPU Clock
Intel SL CPU Detected
(stops and plays here)
I've found out that my BIOS Version/date is: "American Megatrends Inc. 1.00, 10/19/2017", How can I update it?
I've found this page: "https://www.ami.com/products/firmware-tools-and-utilities/bios-uefi-utilities/" but I'm not sure if this is what I need, or what of the four links I should download.
I'm using Windows 10, if there is the need to know other things, just let me know.
Thank in advance!
Ryzen 7 5700x
Aorus B550 Elite AX V2 Rev 1.1
Corsair Vengence RGB Pro 32gb DDR4 3600
Sk Hyinx Platinum P41 SSD PCIe NVMe M.2 2TB
Gigabyte Gaming OC 6750xt
Corsair RM850x
I tried assembling everything outside of the case in case there were any issues. I managed to boot into the American Megatrends screen where is displays: Version 2.20.1271 BIOS Date: 01/04/2022 Ver:15 Press <Del> to enter setup
New CPU installed, fTPM/PSP NV corrupted or fTPM/PSP NV structure changed.
I’ve tried pressing/holding delete on this page and when powering on, but I can’t enter BIOS. I have tried all the usb ports on the motherboard, and tried different F keys to see if that would work. NumLock does light up, so I know it’s connected. And I did press “N” once to “keep previous fTPM” record, so I know that inputs are registered, but I can’t enter the BIOS page.
I have also tried resetting the CMOS, by removing the button battery, but the result is the same.
Any ideas on what to do? I wanted to be able to monitor my specs before installing the whole thing inside the case.
Hello! I just recently booted up my PC as I usually do and the American Megatrends BIOS popped up. I’ve never seen or have this happened to me before so I was a little confused. I went and confirmed everything to get into my PC again, but for some reason I had to remake my PIN-code again? After this I tried rebooting it but the BIOS message doesn’t come up again. I fear I was too quick confirming everything and I am now afraid something could be wrong with my PC after doing some research. Does anyone know why this came up? Is there any way to make it appear again? Should I be afraid considering it doesn’t come up again? Grateful for any help.