Path: utzoo!mnetor!uunet!husc6!ut-sally!ut-emx!ccbw001
From: ccbw001@ut-emx.UUCP (Bob Gustwick)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Multitasking
Message-ID: <422@ut-emx.UUCP>
Date: 3 Jan 88 19:55:52 GMT
References: <234@wybbs.UUCP>
Distribution: na
Organization: The University of Texas at Austin, Austin, Texas
Lines: 80
Keywords: Thanx. OS/2. 80386. etc...
Summary: Quarterdeck's DESQview on 8Mhz V20 XT

In article <234@wybbs.UUCP>, davejag@wybbs.UUCP (Dave Jaglowski) writes:
> My request still stands. Anybody who know of a Multi-Tasker that will really
> work (Its got to be commercial, I can't find any PD that work). This is my
> current setup (I wish..... I wish.... Model 80 for free please!.....)
>  
> IBM XT Chassis.
> NEC V20 a/8Mhz
> 640K DOS Ram
> 128K ram (HELP! No Expanded or Extended memory driver!)
> 2 5 1/4" floppies
> 1 20Meg Seagate
>  
> I would especially appreciate any info on DESQview. How well it works,m etc...
>  

I use DESQview on an 8Mhz V20 Zenith 158 (XT clone).  It is the only product 
I've found that seems to work.  Alas, there are some problems...  not with
DESQview, but with the hardware required to run it.  

DESQview can be run on a 640K PC, but it is not really that useful.  by the 
time you've got memory allocated for DOS, DESQview, you probably only will
have about 300K left to multitask in (I'm guessing, not at home to see for 
sure).  You really need some EMS 3.2 memory for DESQview to swap between 
programs well (like the Mac switcher).  To multitask well under DESQview you 
need some AST or Quadram EEMS memory, or EMS 4.0 memory.  So far, I have been 
unable to find an EEMS card for the PC bus that will run at 8Mhz.  I have AST's
Rampage PC and AST's 6-pack premium.  The 6-pack premium seems to work fine
for all EMS applications except DESQview at 8Mhz.  The Rampage PC consistantly
fails (parity errors) at 8Mhz.  Both come w/ 150ns rams.  I've tried 120ns
rams w/ the same results.  I've called Quadram, but they told me that their
PC boards don't work at 8Mhz either.  So far I've not seen any ads from EMS
board manufacturers proclaiming *hardware* compatibility w/ EMS 4.0.  So
far AST & Quadram seem to be the only choices...  so when I run DESQview, 
its at 4.77Mhz.  AST has a new 80286 accellerator card (HotShot 286) out 
that is compatible w/ EEMS and it has been claimed to have a Norton SI 
rating of 10.1.  Perhaps that will solve my speed problems.

Why is EEMS or EMS 4.0 so necessary???  both of these expanded memory
specifications allow paging of memory in the 640k conventional memory space.
this means that on an XT you might have several 400K dos sessions all 
multitasking away at once.  I have removed all memory from my CPU card in 
my Zenith so that all memory in my machine comes from the EEMS cards...  
I have done such things as have a kermit file transfer and long C compile
in the background while running a flight simulator in the forground.  
admittedly, on a 4.77Mhz V20 too much multitasking can really slow down an 
already slow system.  running two Norton SI's (from the advanced edition) at 
once under DESQview got 0.7 of an IBM XT in each DESQview window.  4.77 Mhz 
V20 w/o DESQview was 1.8, and 8Mhz V20 gets a 2.1 (if i remember correctly).

If your programs don't go thru the standard MSDOS hooks, or can't make 
TopView calls, then your programs can only run in the foreground (when it
has full access to such resources as the screen) but most of the stuff that
i want to have run in the background does so quite nicely (compilers and 
communications programs). 

The process to inform DESQview of program characteristics is much simpler
and less time consuming that Windows 1.0  (I don't have 2.0 so i have no idea
if it is any nicer...  1.0 was a real dog...  and although i got it for free 
w/ the purchase of my machine, i quickly removed it from my hard disk.  
i can only hope that windows 2.0 and OS/2 are much better...  otherwise 
we are surely doomed)  Also unlike windows, you can run a program 
under dos and DESQview assumes that that program is well behaved.  You'll 
notice quite quickly if the program is not well behaved.  But a surprising 
number of programs work quite well.  Windows assumes that no program is 
well behaved and forces you to define each program w/ its own pif file or
in window's config file.  i use lots small programs (pkarc, picnix utilities,
etc.) and would hate to have to define a pif file for each.

Quarterdeck would have me believe that DESQview is even more slick on the 386.
it requires no special hardware by using 386 facilities to simulate EEMS.

In summary, DESQview is the most best multitasker for DOS I've used.  Perhaps 
Windows or OS/2 works well on the 386, but not on my XT clone.  The only 
drawback is that you really must use EMS 4.0 or EEMS hardware to take full 
advantage of DESQview.  One program that I have not used is DoubleDos.  
As its name implies, it can only run 2 programs...  I know of several BBS's
that are running under it...  It may be a solution if you don't want to buy
extra hardware...

...Bob