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From: kls30@duts.ccc.amdahl.com (Kent L Shephard)
Newsgroups: comp.os.msdos.misc
Subject: Re: Multitasking?
Message-ID: <47Xj02Pn04KF01@JUTS.ccc.amdahl.com>
Date: 3 Jan 91 17:03:05 GMT
References: <35.2771BC36@bohemia.metronet.org>
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Reply-To: kls30@DUTS.ccc.amdahl.com (Kent L. Shephard)
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In article <35.2771BC36@bohemia.metronet.org> Greg.Smith@p11.f477.n104.z1.METRONET.ORG (Greg Smith) writes:
>
>To: brucen@CSUFresno.EDU
>
>In a message to All <18 Dec 90 01:47> Bruce Nelson wrote:
>
> BN> I've heard alot about multitasking but not quite sure what true
> BN> multitasking is (according to IBM).
>
> BN> Is there anyone in netland that might be able to tell me what
> BN> "true" multitasking is, which microproccessors (8088, 80286,

True multitasking is just the ability to run several programs at once.
Providing each with a portion of the available resources either in a round
robin fashion or on demeand when a task needs those resources (preemtive).

 
> BN> 80386sx, 80386, 80486) are able to multitask, and what type of
> BN> software allows multitasking.
>True multitasking can only be achieved on the 80386 and up (486, soon
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is not true DESQview multitasks on all 80x86 processors you just have
no process protection on less than a 386.  On less than a 386 an ill
behaved program can write anywhere in memory, including over the OS.
On a 386 and up you get process protection and virtual 8086s so all
processes have what they think is their own register set etc. On a
386 an ill behaved program will cause an exception when it tries to
do something weird. Any processor is capable of multitasking.  You
need hardware for process protection.

>586 etc..)  There is a virtual mode which allows the 386 to act like 4
                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This is limited by you OS and memory not CPU

>8088s, and on the 486, I believe this mode can be extended even further.
>To use these modes, OS/2 is a good operating system for it, or
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Wrong OS/2 is a memory hog and a resource hog.  It only runs one DOS prog.
in the compatibility box, and does a pretty poor job of that.

OS/2 sucks.  If you want preemtive multitasking then get DESQview.  If you
want/need a graphical interface get MS WIN 3.0 (not preemtive program has
to give up control).

>DESQview '386, Windows 3.0 '386.  These are the most common multitaskers

If you want a graphical interface, preemtive multitasking, etc.  Get out
of the DOS world and go UNIX.

>that I know of.
>
>                                   Greg
>
>
>
>
>
>--- XRS 4.00
> * Origin: Greg Makes His Point. (Quick 1:104/477.11)
>
>--  
>=============================================================================
>Greg Smith - via MetroNet node 200:5000/301 
>The Bohemia BBS System, Boulder Colorado (303)449-8946
>UUCP:  Greg.Smith@p11.f477.n104.z1.METRONET.ORG
> or :  ...!boulder!bohemia.METRONET.ORG!1!104!477.11!Greg.Smith
>=============================================================================


--
/*  -The opinions expressed are my own, not my employers.    */
/*      For I can only express my own opinions.              */
/*                                                           */
/*   Kent L. Shephard  : email - kls30@DUTS.ccc.amdahl.com   */