Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!security!genrad!grkermit!masscomp!clyde!floyd!whuxle!pyuxll!abnjh!u1100a!pyuxn!pyuxww!mhuxm!mhuxl!ihnp4!inuxc!pur-ee!uiucdcs!uicsl!preece From: preece@uicsl.UUCP Newsgroups: net.micro Subject: Re: Mac: 16 or 32 bit? - (nf) Message-ID: <5195@uiucdcs.UUCP> Date: Fri, 27-Jan-84 22:38:56 EST Article-I.D.: uiucdcs.5195 Posted: Fri Jan 27 22:38:56 1984 Date-Received: Tue, 31-Jan-84 02:49:17 EST Lines: 25 #R:ihuxi:-78000:uicsl:7000045:000:1112 uicsl!preece Jan 27 07:49:00 1984 I have a Motorola MC68000 users manual that says 16-bit microprocessor on the cover. All the ads for Macintosh say it's a 32 bit micro... Which is it? Being more into hardware , I thought that having D0-D15 made it a 16 bit micro. ---------- This is one of those unanswerable questions. You get to pick whether to classify machines by register width or by external buss width. Either answer may give confusing results. Consider the IBM System/360 family. As I recall, the buss width varied by model within the family from 8 to 64 bits (this is old knowledge and subject to the decay of my memory) and some operations dealt with up to 64 bits at a time, so you pick a size. It's generally thought of as a 32 bit family because most of the registers are 32 bits and that is referred to as the word size in the documentation. More modern processors have more kinds of operands, so there is no 'normal' word size. Clearly, though, the 68000 is an order of magnitude 'bigger' than the 8088, since in both data access width and register width it is twice as wide. scott preece ihnp4!uiucdcs!uicsl!preece