- 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 variety of available video display hardware for Intel PCs is astounding. Because of the range of options, there's a definite need for video BIOSs to control the display of information. On most computers, your only hint of the presence of the video BIOS comes when you first turn on the computera line or two of text flashes by, usually for only a second or so. This text identifies the make and model of video adapter, and possibly the BIOS version number. This information is occasionally helpful in diagnosing problems with video hardware, but video BIOSs seldom provide user-configurable options akin to those for the motherboard BIOS.
Modern video boards sometimes have the capability to use an interrupt request (IRQ) line, which is a way for hardware to request service from the OS. The number of IRQs in a modern PC is quite limited, and many OSs don't use the video IRQ. You might therefore want to disable this feature if you think it's not being used. You can often do so in the motherboard's BIOS. If you disable the video IRQ and then experience problems or poor performance, particularly in 3D games, you should reenable the video IRQ.