- 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
Devices such as sound cards and modems often contain their own BIOSs, or at least BIOS-like features. In general, you don't access these BIOSs the way you do the motherboard or some SCSI BIOSs; you simply let them do their thing and otherwise ignore them.
Some boards include nonvolatile or volatile RAM in which they store information on configuration options to be used across boots. Occasionally this information can become corrupted or settings from one OS can interfere with the operation of another. You might therefore need to boot one OS to configure a board's options before booting another OS. For example, combination sound card/modems built around many of IBM's Mwave chips have drivers only in DOS, Windows, and OS/2. They can be made to work as 8-bit SoundBlaster-compatible sound cards, however, by booting DOS and enabling the board's SoundBlaster-compatible mode and then booting the target OS. It's generally necessary to do a soft reboot (by using Ctrl+Alt+Del) rather than a hard reboot (by using the reset button on the computer's case) when using DOS to initialize hardware for another OS.
Even if you don't want to keep a DOS partition, keeping a DOS boot floppy can be extremely useful for running DOS utilities to diagnose problems with hardware or to fiddle with the BIOSs of some devices.