Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!snorkelwacker!apple!netcom!ergo
From: ergo@netcom.UUCP (Isaac Rabinovitch)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Windows 3.0 is pre-emptive?  (was: Sound Blaster with Windows)
Message-ID: <12061@netcom.UUCP>
Date: 16 Aug 90 15:52:22 GMT
Reply-To: ergo@netcom.uucp
Organization: UESPA
Lines: 45

In <12512@leadsv.UUCP> zech@leadsv.UUCP (Bill Zech) writes:



>Windows 3.0 apparently multitasks DOS programs via a simple time-slice
>algorithm, and anybody familiar with sampling theory can see how
>this will produce bogus results with the music playback code.  The result
>is very intermittent notes.  

Your logic is certainly sound (excuse the pun).  But I'm a little
puzzled as to how this could be happening under Windows.  If it were
happening under DesqView or another pre-emptive multitasker, it'd make
sense.  But it's my understanding that Windows is non-premptive --
that is, a task switch only occurs when a task relinquishes control.
Perhaps W3.0 added pre-emption?

Then again, a task doesn't always relinquish control explicitly, at
least on the source-code level.  I have a cute little litle
non-pre-emptive multitasking package somebody kludged up for Turbo C.
It plants hooks to the "your turn" call in the screen and keyboard I/O
routines, so a task is passing control every time it interacts with
the user.  Perhaps your program is using routines with a similar hook
to Windows?

The above blather may all be a reflection of my total ignorance about
Window.  If anybody has the impulse to educate me, please don't fight
it!

>BTW, I have developer's kits for both the Adlib board and the Sound
>Blaster.  They are better than nothing, but I think they are rather
>poorly packaged and documented for the money.
Not a big suprise.  Really good technical writing costs $30+ a page.
Not much, compared to the cost of hardware and software engineering,
but more than tiny startups are usually willing to pay.  I suppose the
owner/engineers consider their contributions sweat equity, while
hiring a tech writer costs real money.


-- 

ergo@netcom.uucp			Isaac Rabinovitch
atina!pyramid!apple!netcom!ergo		Silicon Valley, CA
uunet!mimsy!ames!claris!netcom!ergo

Disclaimer:  I am what I am, and that's all what I am!