IBM PC/XT emulators
The IBM Personal Computer XT 5160, often shortened to the IBM XT, PC/XT, or simply XT, was a version of the IBM PC with a built-in hard drive. It was released on March 8, 1983. Apart from the Winchester disk, it was essentially the same as the original PC, with only minor improvements. The XT was mainly intended as an enhanced IBM PC for business users. Later floppy-only models would effectively replace the original model 5150 PC. A corresponding 3270 PC featuring 3270 terminal emulation was released later in October 1983. Later, the PC/AT 5170 was released with many enhancements, the most major of which was probably the 286 processor. This allowed a 16-bit bus, which is why 16-bit ISA cards will only work on AT or newer, though some XT-class machines have the older 8086 processor, which also allows for a 16-bit bus, and therefore 16-bit ISA cards.