Message-ID: <327950FF.50B3@gbrmpa.gov.au>
Date: Fri, 01 Nov 1996 09:23:12 +0800
From: Leath Muller <leathm AT gbrmpa DOT gov DOT au>
Reply-To: leathm AT gbrmpa DOT gov DOT au
Organization: Great Barrier Reef Marine Park Authority
MIME-Version: 1.0
To: Avery Lee <Psilon AT concentric DOT net>
CC: djgpp AT delorie DOT com
Subject: Re: Preemptive Multitasking under DPMI
References: <5538hu$2ue AT news DOT latnet DOT lv> <28OCT96 DOT 22083606 AT skyfox DOT usask DOT ca> <32769365 DOT 536643 AT news DOT concentric DOT net> <327810B9 DOT 6FAF AT gbrmpa DOT gov DOT au> <327a2883 DOT 18206970 AT mail DOT concentric DOT net>
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> The command prompt is the greatest thing about Windows 95.  Even my Mac
> friend goes nuts because he has to use an iconic interface when a simple
> command line would be faster...  I do everything from the command line,
> even run Windows programs.  Much easier, less windows.

True...try doing a del *.o on a Mac... :)

> Even on an Amiga I didn't run format commands in the background.  Are you
> crazy!?!? :-)

No, I ran four formats at a time on my A4000...it was used as the backup
machine for the network... :) Did well too... (And I used gcc on it
too!)

> >BUT, where you compiling from the same DOS shell you were formatting
> >from?
> >:)
 
> No, I use multiple shells for that.

Which sux... :)  We really need a
	format a: &
option...
 
> I don't like to do things while formats are in progress.

Why?
 
> >And have some thought for me eh? I am using a Mac here at work...if you
> >think 95 is bad, try MacOS ... ;)
 
> I have.  Brought a Zip disk in FAT format to my friend's powermac.  Stuck
> it in.  Tried to copy a file (huge DOOM wad file) over.  Icon disappeared
> from Zip disk, but the space didn't free up.  Brought the disk back home,
> looked, ran ScanDisk, and discovered that the Mac had only succeeded in
> munging its own DESKTOP.FIL files.
> *sigh*

The Mac also adds its own creator information, and program executor
information.
It really sux when you copy 7 disks w/ 1.44 Mb on each, to get home and
find
out your PC doesn't recognise the file formats... :|
 
> >Onto a different topic:
> >
> >As for DOS multi-tasking, the implementation I will take is to use the
> >uclock timer, select a time slice size - say, 10ms, and run my
> >subroutines
> >from my uclock timer interrupt (well, thats the plan anyway... :) that
> >way my uclock interrupt will decide what gets to run when, and will as a
> >result be fully pre-emptive. I was also looking at having an interrupt
> >run at say 44100 times a second, and use my own sound mixing code. This
> >interrupt would pre-empt my uclock interrupt, having absolute priority.
> >Isnt this pre-emptive multi-tasking? (although its for a dedicated
> >application and I have no idea how I am going to do it yet... :)
 
> That is not entirely preemptive multitasking.  What you are in fact doing
> is running an interrupt task, perhaps cooperative multitasking.  True
> preemptive multitasking requires that you be able to switch foreground
> tasks off interrupt (context switch).  The way you're doing it, you cannot
> preemptively interrupt tasks you run off the interrupt, like sound mixing
> -- you must either run them sequentially the old-fashioned way, or
> implement a cooperative system.  Unfortunately, your way is the only way it
> can be done under DPMI.

Well, now you're getting picky... ;) Cooperative is better than none
after
all (or Sharing like this stoopid PPC 601/120... *ARGH*  (Sorry, this is
the
second time I have written this letter...just love those System 11
errors... ;)
 
> By the way, Rebel Assault II runs the entire game (except for the disk
> read) off the timer interrupt with a cooperatively multitasking system!

Never played it... :)

Leathal.