Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site burl.UUCP Path: utzoo!watmath!clyde!burl!geoff From: geoff@burl.UUCP (geoff) Newsgroups: net.math,net.wanted,att.wanted Subject: need fast algorithm for reciprocal Message-ID: <480@burl.UUCP> Date: Tue, 12-Jun-84 10:28:58 EDT Article-I.D.: burl.480 Posted: Tue Jun 12 10:28:58 1984 Date-Received: Wed, 13-Jun-84 00:24:10 EDT Organization: AT&T Technologies; Burlington, NC Lines: 19 I am working on a very primitive machine which lacks a division operation. What I really need is a reciprocal, so either type algorithm would be fine. I have shift, +,-, and *, as well as logical operators, available. I recall that IBM had an algorithm many years ago which used multiplication to divide (sort of a binary search -- multiply guess * number, compare to 1, adjust guess), but I don't remember it well enough (my attempt at such an algorithm required an avg of 20 iterations for reciprocals of numbers between 2 and 8000). Any help from the net would be sincerely appreciated. thanks, geoff sherwood burl!geoff <"take care of the luxuries and the necessities take care of themselves">