Xref: utzoo comp.sys.mac.misc:12952 comp.windows.ms:13579 Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!sdd.hp.com!mips!apple!voder!nsc!amdahl!rtech!dosbears!mikel From: mikel@dosbears.UUCP (Mike Lipsie) Newsgroups: comp.sys.mac.misc,comp.windows.ms Subject: Re: Mac Vs. Windows? (sorry) Message-ID: <412@dosbears> Date: 6 Jun 91 14:03:24 GMT References: <0E010021.e0mxxc@gla-aux.uucp> <1991Jun4.154854.19649@dbase.A-T.COM> <20@ryptyde.UUCP> Reply-To: dosbears!mikel@pyramid.com (Mike Lipsie) Organization: DOS Bears Lines: 29 In article <20@ryptyde.UUCP> dant@ryptyde.UUCP (Daniel Tracy) writes: > >Well, not really. I'm assuming that even though the segment "window" doesn't >have to be moved, the accessing routine is still slower. The window doesn't >change, but it's still there. In order to request a memory address, a segmented >chip must do an extra multiply (at least) every time. That is, it multiplies >the address location within any segment by the segment being used, so it doesn't >act as linear-addressing at all. Er. This explanation makes me worry about the rest of your logic. It does NOT do a multiply; it does an ADD. The segment register multiplied by 16 is added to the offset register. In 8086 mode this means the _equivalent_ of a four bit shift to the segment register. > The 386+ DOES have a fairly good linear >memory mode, but this isn't used by any OS's except for Unix. Also, there are >many other factors in 680x0 vs 80x86. Intel's line doesn't even come close >in most cases to MC's chip line. Also, because the 80x86 began as 16-bit chips >internally, many kludges had to be performed in order to maintain compatibility >across the line, and thus the 680x0 line is also accelerating past the 80x86 >at a faster clip because it isn't being held back by mode up mode implimentation. You can't be "better" and then "pass the competition". Make up your mind. -- Mike Lipsie dosbears!mikel@pyramid.com mikel%dosbears.uucp@ingres.com