analog computer

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A computer in which numerical data is represented by measurable physical variables, such as electrical voltage or the position of a indicator.

from the GNU version of the Collaborative International Dictionary of English.

• noun a computer that represents information by continuously variable quantities (e.g., positions or voltages).

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A computer (mechanical, electrical or other) that processes using continuously varying signals rather than digital, quantized, values.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a computer that represents information by variable quantities (e.g., positions or voltages)