- The x86 BIOS: Its Limits and Capabilities
- 16- and 32-Bit Code
- The BIOS as Driver for DOS
- Modern Uses of the BIOS
- What BIOS Do You Have?
- Add-On Card BIOSs
- Video BIOSs
- Boot BIOSs for SCSI and Networking
- Additional BIOSs
- BIOS Updates
- EIDE and SCSI Hard Disk Handling
- Understanding CHS Geometry Limits
- Getting Around the 1024-Cylinder Limit
- Common BIOS Disk Utilities
- The Handoff to the OS
The BIOS for Intel x86-based computers is steeped in history and is the software component that, on most systems, bears the strongest relics from the modern PC's past as a 16-bit computer designed in the early 1980s. Nonetheless, the BIOS is an extremely important piece of software because it controls an assortment of hardware options and because it handles the beginnings of the boot process.
A variety of BIOSs exist for modern computers. Each motherboard comes with its own BIOS, and several companies produce BIOSs that are licensed by motherboard manufacturers. In addition to the main motherboard BIOS, most computers have one or more BIOSs on plug-in cards such as video adapters, SCSI adapters, and network cards. Each of these BIOSs extends the capabilities of the motherboard's BIOS.
After they're booted, most modern OSs more or less ignore all BIOSs, instead using their own drivers to access the hardware directly. A few OSs, however, such as DOS, continue to rely on the BIOS for access to at least some hardware components.