| Q | A very high level language, implemented in C++. 2. Quadrature. |
| QA | Quality Assurance. Procedures taken to ensure that a company delivers products that conform to standards. |
| QAM | Quadrature Amplitude Modulation. A technique of modulation in which there are sixteen possible four-bit patterns, determined by the combination of phase and amplitude. |
| QBASIC | The version of QuickBASIC that comes with DOS 5 and later versions. It replaces, and accepts programs written for, Microsoft's GW-BASIC. |
| QBE | Query By Example. A user-friendly way of querying a database that was originally developed by IBM for use with mainframes, and later adopted by many other systems. With Query By Example, an empty record is displayed and the user types in the search keys; for example, typing "New York" in the "city" field will return all records where the city is New York. |
| Qbench | A DOS hard disk benchmark from Quantum Corporation, which measures data access time and data transfer rate. |
| QDOS | Quick And Dirty Operating System. An early personal computer operating system rumored to be the forerunner of PC-DOS and MS-DOS. 2. An operating system designed for the Sinclair QL computer. |
| QEMM | Quarterdeck Expanded Memory Manager. A DOS and Windows memory manager from Quarterdeck Office Systems, Santa Monica, California; used for IBM PCs with an Intel 80386 or higher processor. |
| QIC drive | (Quarter Inch Cartridge drive). A drive used to back up personal computer data on quarter inch cartridges. |
| QIC tape | Quarter Inch Cartridge tape. A magnetic tape used for backing up data, which comes in hard cartridges. QIC tape comes in minicartridges (3.5") and data cartridges (5.25"). There are various types of cartridges and lengths of tape, storing from 40 megabytes to 25 gigabytes of data. |
| QIC Wide | Quarter Inch Cartridge Wide. A quarter inch cartridge tape from Sony that is wider than 1/4 inch. It is .315" wide and has a greater recording density, thus increasing the storage capacity. |
| QIC-EX | Quarter Inch Cartridge - Extended. These magnetic tape cartridges come in both .25" and .315" formats and contain longer tape to extend the storage capacity of the quarter inch tape drives. |
| QL | (Quantum Leap). A personal computer developed by Sir Clive Sinclair and first released in 1983. It is based on the Motorola 68008 microprocessor and uses an operating system called QDOS developed by Sinclair. |
| QMS | Quality Micro Systems. A Mobile, Alabama manufacturer of laser printers. QMS made one of the first PostScript printers. |
| QTW | QuickTime for Windows. Multimedia software from Apple Computer that integrates full-motion video and sound into application programs. |
| quad | Two bits (a quarter of a byte). |
| quad-speed CD-ROM drive | (4X) A CD-ROM drive that can read information four times as fast as a music CD. At least a double speed drive is needed for multimedia CD-ROMs, and quad speed is even better. |
| quad-speed drive | A CD-ROM drive that is four times as fast as a single-speed drive. Quad-speed drives substantially improve the quality of multimedia. |
| Quadra | A brand name for one of the Macintosh series of computers. |
| quadrature | (Q). At 90 degrees to a reference. |