PC Hacks

Hack #11. Step Away from the Legacy Device

As the Borg proclaim in many Star Trek episodes, "Resistance is futile. You will be assimilated." So will you find emphasis on moving PC I/O capabilities and devices as far away as possible from legacy technology. ISA technology is bigger, bulkier, and fraught with more configuration complexities and conflicts than the vendors and their support people ever imagined, and it's been more than a bit frustrating for millions of PC users as well. The best way to avoid the rest of this chapter and a lot of frustration and to gain a lot of performance and reliability is to disconnect, remove, disable, and replace all of your legacy devices with PCI, PCI-X, AGP, USB, or IEEE-1394 products.

With systems that provide enough 8- or 16-bit ISA slots (typically the black-colored edge connectors on your system board) to allow you to fill the system up with a lot of ISA devices, it is not unusual to run out of IRQs (Interrupt Request lines), limited resources that the CPU uses to address devices. Over the past few years the number of ISA slots on any given system board has decreased (often to zero) while the number of PCI slots (typically white edge connectors) has increased, and even the number of PCI slots is decreasing as more common functions (network, video, sound) have been built onto the system board. PCI devices do not have the same problems with IRQs that ISA cards have: PCI devices can share IRQs, and modern motherboards can assign IRQs dynamically ...