Path: utzoo!censor!geac!maccs!cs4g6ag From: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn) Newsgroups: comp.sys.ibm.pc Subject: Re: Brain-dead 286 - summary Message-ID: <25F7F56B.11734@maccs.dcss.mcmaster.ca> Date: 9 Mar 90 18:26:50 GMT References: <8681@rosevax.Rosemount.COM> <29405@amdcad.AMD.COM> Reply-To: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn) Distribution: usa Organization: McMaster University, Hamilton, Ontario Lines: 114 In article <29405@amdcad.AMD.COM> phil@pepsi.AMD.COM (Phil Ngai) writes: $In article <8681@rosevax.Rosemount.COM> marknew@rosevax.UUCP (Mark Newman) writes: $|From Raymond Chen (raymond@math.berkeley.edu): $| There is no way to switch from protceted mode to real mode on a 286. $Of course not. What good is a protected mode if a random program $can violate it? Nobody ever said anything about allowing random chips to do it ... one of the big parts of having multitasking support is the provision of different privilege levels to different processes. The 80286, I believe, has four such levels. The privilege level of a process determines such things as what opcodes it can execute (for example, I/O is usually a no-no for low-privilege processes). By having an instruction at the highest privilege level that allows a switch back to real mode, random programs couldn't execute it (attempts to execute privileged instructions by non-privileged processes generate an interrupt which the OS has to handle). $|From Dean William Wallwey (wallwey@snoopy.colorado.edu): $| The 386 and 386SX both have very powerful memory mapping powers which $| are used by the new operating systems. $What new operating systems are you thinking of? Unix, perhaps? Possibly ... perhaps also the forthcoming 386-only version of OS/2. And if you call an EMS driver part of the operating system (and there are some grounds for making such a statement), that's another example. $| calls Virtual 86 mode so you can multitask DOS programs using Windows $| or DesqView for the 386. The small amount of money you save by buying $I still don't believe the DV386 uses virtual 86 mode. Does anyone have $any definitive data? Maybe I'll ask QD. I don't use DV or Windows, but it would make no sense to have a 386- specific version of a multitasking OS that allowed you to run DOS programs but didn't use the virtual 86 mode. $| The 386,386SX and 486 will $| run OS/2, mulitasking DOS, and UNIX, MUCH MUCH better than the 286 $| ever will. Even the new Windowing word processors from MicroSoft $Unix does run better on 386 and 486. I don't know what you mean by $multi-tasking DOS. It is quite possible to write an operating system, running on the 386, that uses multiple virtual 8086s and identical function calls to DOS which allows DOS program to be multitasked. There are already programs out there which do this with varying amounts of success. $| Even if you don't think that you'll need the power of the 386 group, $| you will soon see even the simple "home" programs like word pro- $| cessing and spreadsheets longing for the 386/386SX. (I guess they $| already do with WORD for WINDOWS, and Lotus 1-2-3 ver 3.0 even though $| they will "run" on a 286). $I don't think you know what you are talking about. Maybe you don't ... have you ever tried using a program like 1-2-3 R3 on a 286? Even on a 12 MHz 286, the program is a pig. From what I've heard, Word for Windows is also a pig. There are two distinct machine configurations for software: the absolute minimum system below which the program will not run at all, and the minimum practical system below which the program will run painfully slowly. For 1-2-3 R3, for example, the absolute minimum is a 286 with 1M of conventional + extended memory and a hard disk. The minimum practical system would have at least 2M of RAM and a processor running at 20 MHz or more. (Note that I'm talking DOS here ... 1-2-3 R3 for OS/2 absolutely requires something like 3 or 4M of memory). $With Windows 3.0, which does run in protected mode on a 286, due to $come out early this summer, you should consider exactly what the $extra cost of a 386 will buy you. Hold on a minute here ... what's the extra cost of a 386? For a 386SX system, we're talking a couple of hundred dollars difference between a 12 MHz 286 and a 16 MHz 386SX (more if you don't have a clue where to buy your system). For this you get the ability to run 386 software (which will become more prevalent in the future) and about 20-25% more speed. Not bad for the price. $|From John Limpert (johnl@n3dmc.UU.NET): $| In the future $| there will be a lot of software that will only be available for 80386 $| class machines. $Again, there is a very large market for 286 applications and they $simply will not be left unsupported. Nobody's saying that ... what people _are_ saying here, if you'd care to listen, is that software is being written that takes advantage of the 386, and more software will be written that way in the future. Nobody has said "Two years from now, all software will require a 386", because that's ludicrous. What will happen, though, is that more and more software will either take advantage of a 386 if you have one (like PKZIP), or will be written specifically to run on a 386 (you want examples? Look through a copy of BYTE. You'll see operating systems, compilers, database products - all applications where high performance is crucial, and all available in versions that require a 386). $Certainly Unix is one program that benefits from a 386. But users $don't buy PCs to run Unix, they buy PCs to run applications, and $Unix is one of the worst systems to try to buy applications for. $What kind of spreadsheets can you get? Anything that comes even $close to Excel? I hear you can finally get MS Word 5.0 on Unix. $A character based application, when DOS has Word for Windows. If $you've got the Unix religion, I guess you'll get a 386. But if $you want to get work done, you'll stay away from Unix. Well, you're perfectly entitled to voice your opinions on what operating system you want to use, what applications you want to use, and whether you want character-based or graphical interfaces. Just don't delude yourself into believing that everyone else has the same needs or desires that you do. -- Stephen M. Dunn cs4g6ag@maccs.dcss.mcmaster.ca = "\nI'm only an undergraduate!!!\n"; **************************************************************************** "Oooh yes I need some love" - Rush