Stands for Electronics Industry Standards Association. A group of computer manufacturers that joined together to define a new expansion bus for the PC. The expansion bus the group defined is called an EISA bus and it is a rival to the MCA bus that was developed by IBM. Both buses allow expansion cards to take control of the PC and so improve the speed at which data is transferred between the expansion card and the PC. Most PCs have an ISA expansion bus which allows 16 bits of data to be transferred. The EISA and MCA buses allow 32-bits of data to be transferred. The big advantage that EISA has over MCA is that you can still use the older ISA expansion cards in an EISA slot, whereas an MCA expansion slot will only work with special MCA cards. (See also ISA and MCA.)
