scan

1. (computer peripheral) See scanner.

2. (circuit design) See scan design.

3. (functional programming) See scanl, scanr.

4. storage, algorithm An algorithm for scheduling multiple

accesses to a disk. A number of requests are ordered

according to the data's position on the storage device. This

reduces the disk arm movement to one "scan" or sweep across

the whole disk in the worst case. The serivce time can be

estimated from the disk's track-to-track seek time, maximum

seek time (one scan), and maximum rotational latency.

Scan-EDF is a variation on this.

(1995-11-15)