The Industry Standard Architecture (ISA) is a computer bus that allows for additional expansion cards to be connected to a computer’s motherboard. The ISA bus was introduced in 1981 and eventually replaced by the Peripheral Component Interface (PCI) in the mid-1990s.
What is the ISA Bus and What Does it Do?
The ISA bus is a type of bus that facilitates communication between various peripheral devices connected to a motherboard. These devices can include video cards, network cards, and additional serial ports, among others. The ISA bus allows for direct memory access and assigns each expansion card its own interrupt request (IRQ), making it a versatile and dependable bus architecture for IBM-compatible PCs.
The Evolution of the ISA Bus
The original 8-bit version of the ISA bus was introduced in 1981, with the 16-bit version following in 1984. Competing technologies such as MCA and VLB were also available but the ISA bus remained the most widely used expansion bus for most of the 1980s and 1990s. By the end of the 20th century, ISA connectors were gradually phased out in favor of faster and more efficient PCI and AGP slots.
What types of devices can be connected to the ISA bus?
The ISA bus can support a wide variety of expansion cards or peripherals, including video cards, network interface cards, sound cards, and more.
What replaced the ISA bus?
The ISA bus was eventually replaced by the Peripheral Component Interface (PCI) in the mid-1990s.
Is the ISA bus still used today?
No, the ISA bus has been largely phased out in favor of faster and more efficient bus architectures.
The Bottom Line
The Industry Standard Architecture (ISA) bus was once a widely used technology that allowed for the expansion of peripheral devices on IBM-compatible PCs. While it has largely been replaced by faster and more efficient bus architectures, it remains an important part of computing history that paved the way for future advancements in computer technology.