The Software Choice
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Until recently the only software choice open to a PC user
was witch version of MS-DOS (PC-DOS)to run ! MS-DOS was defanged to work with
the 8088/86 and is subject to the well know 648 Kbyte limit on memory . in
addition all the programs that run under MS-DOS were written for the 8088/86 As
has already been mentioned the 286 and
the 386 can pretend to be high speed version of the 8080/8086 and as such can
quite happily run MS-DOS and all the
programs that run under it. if all you want to do is run MS-DOS and
MS-DOS performance is processes clock speed and in this case you could do just
as well with a 286 system with a fast enough clock. However there are still
reasons to prefer a 386 based system and these are concerned with its use of
memory.
Memory Manege meant
Even if you intend to say with MS-DOS you can still benefit
form a 386 machine br adding a memory manager such as from QEMM or 386MAX or by
using EMM386 which is included with MS-DOS 5.The 386 has the ability to
rearrange the layout of memory in a machine memory manager can make use of this ability to move parts of MS-DOS such as
network drives etc. out of the usual 640 Kbyte area and so increase the
proportion of it that is available to applications programs. This is usually
referred to as making use of upper memory blocks(or UMBs) which are discussed
in more detail later.
Expended Memory
Expended memory is a type of memory used by order MS-DOS
programs needing to use more than 640 Kbyte In non 386 based machine expended
memory has to be implemented expanded memory using nothing but software. you
can by utilis that do nothing but crate expanded memory-so called Limulators
but in a full 386 memory manger of the
type described in the previous situation.
DOS Extenders
Some software Louts 1-2-3 Release 3 being the best known,
makes better use of the 386 boys by
incorporating DOS extenders. in this case you can only run the application on a
286 or 386 under MS-DOS but the application has access to all of the memory
installed on the machine. In other Words DOS extenders are nothing more than a
way around the 640KByte limit.
To get the best out the 386 the is no doubt that you have to
move to something beyond MS-DOS.There are varies alternatives some of witch don't involve a complete abandonment
of MS-DOS.
DOS multi-taskers
A DOS multi tracker makes use of the 386's ability look like more than one
complete 8088/86 system run multiples copies of MS-DOS and application. The
Best know does multi tracker are windows
3 and DESK view. both will allow you to run multiple DOS application and switch
between them but window 3 goes some what further it also supporters its own
type of application that isn't limited by the 640kbyte barrier.In this sense Windows 3 is hallway to
binging a completely new operating system that replaces MS-DOS.
New operating system
The most attractive solutions from the technical point of
view at least is to get rid or MS-DOS and all its limitation and starts again
with a more appropriate operating system.this is exactly what Microsoft and IBM
intended to happen when they designed OS/2 but for various reasons the first
versions of OS/2 were eclipsed by windows 3.only IBM is currently making any
effort to develop OS/2 as a challenged to windows 3.OS/2 version 2 was written
specifically for the 386 and it will run MS-Dos windows and OS/2 application on
a nearly acaule footing Microsoft have more or lees abandoned OS/2 to develop
windows NT which is completely new operating system that will run MS-DOS and
windows application on a 386 and perhaps even on other type of prosper. so at the time of writing
the composition is between windows 3.1 and OS/2 Version 2 but in the longer term the battle line -up will changed
to be Windows NT versus OS/2.
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