PC-compatible BIOS developed and sold by American Megatrends since 1986. In 1994, the company claimed that 75% of PC clones used AMIBIOS. It is used on motherboards made by AMI and by other companies. American Megatrends has a strict OEM business model for AMIBIOS: it sells source code to motherboard manufacturers or customizes AMIBIOS for each OEM individually, whichever business model they require. AMI does not sell to end users, and itself produces no end-user documentation or technical support for its BIOS firmware, leaving that to licensees. However, the company published two books on its BIOS in 1993 and 1994, written by its engineers. During powerup, the BIOS firmware displays an ID string in the lower-left-hand corner of the screen. This ID string comprises various pieces of information about the firmware, including when it was compiled, what configuration options were selected, the OEM license code, and the targeted chipset and motherboard. There are 3 ID string formats, the first for older AMIBIOS, and the second and third for the newer AMI Hi-Flex ("high flexibility") BIOS. These latter are displayed when the Insert key is pressed during power-on self-test. The original AMI BIOS did not encrypt the machine startup password, which it stored in non-volatile RAM. Therefore, any utility capable of reading a PC's NVRAM was able to read and to alter the password. The AMI WinBIOS encrypts the stored password, using a simple substitution cipher. By pressing the Delete key during power-on self-test when a prompt is displayed, the BIOS setup utility program is invoked. Some earlier AMIBIOS versions also included a cut-down version of the AMIDIAG utility that AMI also sold separately, but most later AMI BIOSes do not include this program as the BIOS DMI already incorporates detailed diagnostics. AMIBIOS is only sold through distributors, not directly available from the manufacturer or from eSupport. AMI supplies both DOS and Windows firmware upgrade utilities for its own motherboards. eSupport only supplies a Windows upgrade utility. AMIDiag AMIDiag is a family of PC diagnostic utilities sold to OEMs only. The AMIDiag Suite was introduced in 1991 and made available for MS-DOS, Microsoft Windows and Unified Extensible Firmware Interface (UEFI) platforms. It includes both the Windows and DOS PC diagnostics programs. Later versions of AMIDiag support UEFI, which allows diagnostics to be performed directly on the hardware components, without having to use operating system drivers or facilities. Aptio AMI's UEFI firmware