What are ISA expansion slots?
ISA expansion slots are 8-bit and 16-bit bus slots found in older computers. They were first introduced in the original IBM PC (8-bit only) in 1981. 16-bit ones were introduced in the IBM PC AT in 1984. Because of the PC 99 standard introduced by Intel and Microsoft, computers introduced after January 1, 2000 cannot have ISA slots and be certified to run Windows at the same time, so they are only found in older or special-purpose hardware these days.
