BIOS

BIOS, in computing, stands for basic input/output system.

Firmware on adapter cards

A computer system can contain several BIOS firmware chips. In addition to the boot BIOS, which contains code to access fundamental hardware components such as the keyboard or the floppy drive, plug-in adapter cards such as SCSI or USB hard disk adapters or network cards or video boards may include their own BIOS, complementing or replacing the system BIOS code for the given component.

Related Topics:
Floppy drive - SCSI - USB - Network cards

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To find these memory mapped expansion ROMs during boot, PC BIOS implementations scan real memory from 0xC8000 to 0xF0000 on 2 kilobyte boundaries looking for a 0x55 0xaa signature, which is immediately followed by a byte indicating the number of 512 byte blocks the expansion ROM occupies in real memory. The BIOS then jumps to the offset immediately after the size byte, at which point the expansion ROM code takes over and uses BIOS services to provide a user configuration interface, register interrupt vectors for use by post-boot applications, or display diagnostic information.

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For UNIX and Windows/DOS systems there is a utility with which you can dump your BIOS firmware software at http://www.linuks.mine.nu/ree/

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