Search results
Results from the WOW.Com Content Network
On system with BIOS firmware, the BIOS invokes MBR boot code from a hard disk drive at startup. The MBR boot code and the VBR boot code are OS-specific. In Microsoft Windows, the MBR boot code tries to find an active partition (the MBR is only 512 bytes), then executes the VBR boot code of an active partition.
UEFI requires the firmware and operating system loader (or kernel) to be size-matched; that is, a 64-bit UEFI firmware implementation can load only a 64-bit operating system (OS) boot loader or kernel (unless the CSM-based legacy boot is used) and the same applies to 32-bit.
Unix, Linux, OS/2, Windows NT are considered modern OS's as they switch the CPU into protected mode at startup, never return to real mode and provide all of the benefits of protected mode all of the time. 64-bit operating systems use real mode only at startup stage, and the OS kernel will switch the CPU into long mode. [2]
In computing, BIOS (/ ˈ b aɪ ɒ s,-oʊ s /, BY-oss, -ohss; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the booting process (power-on startup). [1]
BIOS interrupt calls perform hardware control or I/O functions requested by a program, return system information to the program, or do both. A key element of the purpose of BIOS calls is abstraction - the BIOS calls perform generally defined functions, and the specific details of how those functions are executed on the particular hardware of the system are encapsulated in the BIOS and hidden ...
The main editions also can take the form of one of the following special editions: N and KN editions The features in the N and KN Editions are the same as their equivalent full versions, but do not include Windows Media Player or other Windows Media-related technologies, such as Windows Media Center and Windows DVD Maker due to limitations set by the European Union and South Korea ...
The first stage of PC boot loaders (FSBL, first-stage boot loader) located on fixed disks and removable drives must fit into the first 446 bytes of the master boot record in order to leave room for the default 64-byte partition table with four partition entries and the two-byte boot signature, which the BIOS requires for a proper boot loader ...
BIOS POST card for ISA bus BIOS POST card for PCI bus Professional BIOS POST card for PCI bus Two POST seven-segment displays integrated on a computer motherboard. The original IBM BIOS made POST diagnostic information available by outputting a number to I/O port 0x80 (a screen display was not possible with some failure modes). Both progress ...