ISA (IBM Standard Architecture)
- connects only to a card that has an 8-86,186 or 286 processor, and in which the processor addressing and IBM PC architecture addressing limitations.
- ISA Bus memory in two ranges: 640kb to 1MB or 15MB to 16MB.
- The instruction set provides 64k I/O, the ISA ignores A10 to A15 addresses and therefore only 1024 I/O port addresses are available.
- EISA (Extended ISA) works for 32 bit data and address lines version of ISA.
PCI and PCI-X Buses
- Peripheral Component Interconnect
- Platform Independent (Connects to any architecture and not like ISA)
- PCI provides three types of synchronous parallel interfaces a) 32/33 MHz b) 64/66MHz and PCI-X supports 64/100MHz
Later two super speed versions of PCI have been introduced
- PCI Super – 264/528 MBps at 3.3V on a 64 bit bus
- PCI Super – 132/264 Mbps on a 32 bit bus
- PCI-X Super – 800 MBps on a 64 bit bus at 3.3V