What are the improvements of the E.I.S.A bus over the I.S.A bus? other than transfer rate.?

Question

Extended Industry Standard Architecture - E.I.S.A
Industry Standard Architecture - I.S.A

Answer 1

Lunte...

Since about 1984, the standard bus for PC I/O functions has been named ISA (Industry Standard Architecture). It is still used in all PCs to maintain backwards compatibility. In that way modern PCs can accept expansion cards of the old ISA type.

ISA was an improvement over the original IBM XT bus, which was only 8 bit wide. IBM's trademark is AT bus. Usually, it is just referred to as ISA bus.

ISA is 16 bit wide and runs at a maximum of 8 MHz. However, it requires 2-3 clock ticks to move 16 bits of data. The ISA bus works synchronous with the CPU. If the system bus is faster than 10 MHz, many expansion boards become flaky and the ISA clock frequency is reduced to a fraction of the system bus clock frequency.

The ISA bus has an theoretical transmission capacity of about 8 MBps. However, the actual speed does not exceed 1-2 MBps, and it soon became too slow.

However in the 1980s a demand developed for buses more powerful than the ISA. IBM developed the MCA bus and Compaq and others responded with the EISA bus. None of those were particularly fast, and they never became particularly successful outside the server market.

EISA was developed in 1988-89. It is designed by the "Gang of Nine:" the companies AST, Compaq, Epson, Hewlett-Packard, NEC, Olivetti, Tandy, Wyse and Zenith. It came in response to IBM's patented MCA bus.

EISA is built on the ISA bus; the connector has the same dimensions and old ISA cards fit into the slots. To keep this compatibility, the EISA bus works at maximum 8 MHz. Like ISA, the bus bus is synchronous with the CPU at a clock frequency reduced to a fraction of the system bus clock frequency.

EISA is compatible with ISA in the sense that ISA adapters can be installed in EISA slots. The EISA adapters hold a second level of connectors in the button of the slot.

However, EISA is much more intelligent than ISA. It has bus mastering, divided interrupts and self configuration. It is 32 bit wide, and with it's compressed transfers and BURST modegives a highly improved performance.

But, like the MCA, it did not have great success. Yet the EISA bus is still used in some servers.

Hope this helped

DM

MCP MCSA MCSE+S BIT

Answer 2

EISA has a software-assisted bus line configuration available to it, but ISA does not; you have to mentally clear to deal with ISA bus configuration problems.

And EISA is 32-bit, ISA is 16.

Answer 3

higher bandwith and clock speed at a guess