Industry Standard Architecture The most common bus architecture on the motherboard of MS-DOS computers. The ISA bus was originally pioneered by IBM on its PC, then its XT and then its AT. ISA is also called the classic bus. It comes in an 8-bit and 16-bit version. Most references to ISA mean the 16-bit version (which carries data at up to 5 megabytes per second).- Category ID : 55449