| Term | Description |
| XGA | Extended Graphics Array. A proprietary video card developed by IBM that produces a resolution of 1024 X 768 pixels and can display 256 colors. It only works on IBM machines. |
| XMS | Extended Memory System. In DOS, Extended Memory is that memory above the initial 1024K. |
| XT | Stands for Extended Technology. The IBM PC/XT, released around 1983, was the first IBM PC with a hard drive. |
| ZIF | Zero Insertion Force. It wasn't always easy to get a CPU into (or out of) a friction fit socket without bending pins or chipping the Processor. The ZIF socket has a small lever on the side of it. When you lift the lever, the CPU will just drop in, and as the lever is closed, even pressure is applied to the pins of the processor. |
| Zone Bit Recording | In older hard drives, there were the same number of sectors on the tracks near the center of the platter or disk as there was in the outer tracks. Although the sectors all held 512 bytes, the physical size of the outside sectors was much larger. Zone Bit Recording is a method of dividing up drives so that sectors are all the same physical size and the outside tracks contain more sectors than the inside tracks. |