Extended Industry Standard Architecture

Definition of Extended Industry Standard Architecture

Extended Industry Standard Architecture (EISA) is a computer bus architecture developed in the late 1980s as an enhancement to the Industry Standard Architecture (ISA). It was designed to offer improved performance, increased data transfer rates, and support for 32-bit processors while maintaining backward compatibility with ISA cards. EISA was primarily used in high-end PC systems but was eventually replaced by the Peripheral Component Interconnect (PCI) bus architecture in the 1990s.


The phonetic pronunciation for Extended Industry Standard Architecture can be broken down as:Extended: /ɪkˈstɛndɪd/Industry: /ˈɪndəstri/Standard: /ˈstændərd/Architecture: /ˈɑrkɪtɛktʃər/Putting it together, the phonetic pronunciation can be:/ɪkˈstɛndɪd ˈɪndəstri ˈstændərd ˈɑrkɪtɛktʃər/

Key Takeaways

  1. Extended Industry Standard Architecture (EISA) was an enhancement of the original ISA, providing 32-bit bus architecture for computers, maintaining backward compatibility with 16-bit ISA devices.
  2. EISA was designed in response to IBM’s proprietary Micro Channel Architecture (MCA), offering a non-proprietary expansion bus alternative for PCs and facilitating easier upgrades and improvements.
  3. Despite its technical advantages, EISA lost market share to the simpler, cheaper and faster PCI standard in the early 1990s and eventually became obsolete.

Importance of Extended Industry Standard Architecture

The Extended Industry Standard Architecture (EISA) is an important technology term because it represents a significant advancement in computer hardware design during the late 1980s and early 1990s.

Developed as a response to IBM’s proprietary Micro Channel Architecture (MCA), EISA provided an open standard for 32-bit expansion cards, enhancing the capabilities of PCs and allowing for better overall system performance.

Its backward compatibility with the previously popular 16-bit Industry Standard Architecture (ISA) ensured that existing hardware investments were preserved, which made EISA an appealing choice for businesses and individuals.

Additionally, EISA’s non-proprietary, royalty-free nature encouraged widespread adoption and competition among manufacturers, fostering innovation and growth within the computer industry.


Extended Industry Standard Architecture (EISA) was developed as an improvement to the earlier Industry Standard Architecture (ISA) technology, which was originally used for connecting peripheral devices to a computer’s motherboard. EISA’s primary purpose was to enhance the compatibility and functionality of computer hardware components, thereby opening doors for more sophisticated systems.

It was designed during the late 1980s by a consortium of major computer manufacturers, such as Compaq, Hewlett-Packard, and IBM, with the intent to counter Intel’s proprietary Micro Channel Architecture (MCA) and offer a more accessible and flexible option for advanced computing systems. EISA addressed some of the limitations of the ISA bus by enabling both 8-bit and 16-bit operations, and it also introduced the 32-bit data bus, which significantly increased data transfer rates between components.

This made it an attractive solution for supporting advanced peripherals such as network cards, graphics cards, and storage controllers. Moreover, EISA provided increased expandability, better overall performance, and enhanced compatibility with a range of hardware components, which was vital for the constantly evolving technology landscape of that era.

Despite its eventual decline due to the emergence of more advanced alternatives such as the Peripheral Component Interconnect (PCI) standard, EISA played a crucial role in the development and progress of personal computing hardware.

Examples of Extended Industry Standard Architecture

Extended Industry Standard Architecture (EISA) is a bus architecture that was developed in the late 1980s as an extension of the ISA bus, aimed at providing improved performance and addressing the limitations of the ISA bus. While EISA technology is now largely obsolete, here are three real-world examples from the time when it was more prevalent:

Compaq SystemPro: Launched in 1989, the Compaq SystemPro was one of the first computers to implement the EISA bus architecture. This server system targeted the business market and aimed to deliver enhanced performance and flexibility, with improved data transfer rates, thanks to the EISA technology.

HP Vectra 486/66: Hewlett-Packard’s Vectra 486/66, introduced in the early 1990s, was a computer workstation utilizing the EISA architecture. It featured a 66MHz Intel 486 processor, along with multiple EISA and ISA expansion slots offering increased performance, flexibility, and hardware compatibility.

AST Bravo LC 4/66d: Released in the early 1990s, the AST Bravo LC 4/66d was a desktop computer which featured both ISA and EISA expansion slots, allowing users to take advantage of the higher performance EISA technology while maintaining backward compatibility with existing ISA devices. The computer was powered by a 66MHz Intel 486 processor and was primarily targeted at business users.

Extended Industry Standard Architecture (EISA) FAQ

1. What is the Extended Industry Standard Architecture (EISA)?

The Extended Industry Standard Architecture, or EISA, is a 32-bit computer bus which was introduced by Compaq, Hewlett-Packard, AST Research, Epson and NEC among others in 1988. It was designed as an extension to the 16-bit Industry Standard Architecture (ISA) to increase the performance and capabilities of personal computers.

2. Why was EISA created?

EISA was created to address the limitations of the ISA bus and provide a higher-performance alternative to the proprietary Micro Channel Architecture (MCA) being developed by IBM. EISA was designed to be backwards compatible with existing ISA hardware and software, making the transition easier for computer manufacturers and users.

3. How does EISA differ from ISA?

EISA is an extension of the ISA bus that features several improvements, including a faster 32-bit architecture, support for more devices, better multitasking capabilities, and improved bus mastering capabilities. EISA also provides faster data transfer rates than ISA, making it well-suited for high-performance applications.

4. Is EISA backwards compatible with ISA?

Yes, EISA was designed to be backwards compatible with ISA, which means that existing ISA hardware can be used in an EISA system without modifications. This was a critical feature for the acceptance of EISA, as it allowed manufacturers and users to transition easily to the new standard without having to replace their existing equipment.

5. How does EISA compare to other bus architectures, like MCA and VESA Local Bus?

EISA was developed as an open, high-performance alternative to IBM’s proprietary Micro Channel Architecture (MCA). While EISA did not achieve the same widespread adoption as the VESA Local Bus (VLB), which was simpler and less expensive to implement, EISA still offered significant advantages over both ISA and MCA, such as higher-performance 32-bit data transfers and better compatibility with existing hardware and software.

6. Is EISA still used today?

EISA has been mostly replaced by newer standards, such as the Peripheral Component Interconnect (PCI) and PCIe, which offer even higher performance and greater versatility. While EISA may still be found in some legacy systems, it is generally considered obsolete and is no longer widely used in modern computer systems.

Related Technology Terms

  • Bus Architecture
  • 32-bit Expansion Slots
  • Backward Compatibility
  • ISA (Industry Standard Architecture)
  • Computer Hardware Components

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