From: Darren New <dnew@san.rr.com>
Subject: Re: Multitasking theory question
Date: Tue, 25 Jun 2002 05:17:05 GMT
Date: 2002-06-25T05:17:05+00:00 [thread overview]
Message-ID: <3D17FCEE.B24B69D8@san.rr.com> (raw)
In-Reply-To: WCSR8.355$Ye2.71695719@newssvr13.news.prodigy.com
tmoran@acm.org wrote:
> As to DOS, IIRC there were system calls explicitly to allow you to
> run while a system call was blocking its caller.
No. There was a system call to tell you whether the interrupt routine had
been entered while DOS was already active. If you called DOS again while
this was set, you scragged the stack frame and crashed the machine. DOS
switched to its own stack area when you called it, and switched back when
you returned, and this prevented *anything* from being reentrant in DOS.
--
Darren New
San Diego, CA, USA (PST). Cryptokeys on demand.
** http://home.san.rr.com/dnew/DNResume.html **
** http://images.fbrtech.com/dnew/ **
My brain needs a "back" button so I can
remember where I left my coffee mug.
next prev parent reply other threads:[~2002-06-25 5:17 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-06-20 20:46 Multitasking theory question Kai Schuelke
2002-06-20 20:53 ` Stephen Leake
2002-06-21 2:13 ` Ted Dennison
2002-06-24 3:18 ` AG
2002-06-24 4:13 ` tmoran
2002-06-24 4:24 ` AG
2002-06-24 7:33 ` Dale Stanbrough
2002-06-25 3:27 ` AG
2002-06-25 4:48 ` tmoran
2002-06-25 5:00 ` AG
2002-06-25 5:17 ` Darren New [this message]
2002-06-25 5:25 ` AG
2002-06-24 5:43 ` Mark Biggar
2002-06-24 6:48 ` AG
2002-06-24 15:14 ` Darren New
2002-06-24 16:19 ` Larry Kilgallen
2002-06-25 2:01 ` AG
2002-06-25 3:21 ` Darren New
2002-06-25 4:01 ` AG
2002-06-25 4:19 ` Darren New
2002-06-25 4:51 ` AG
2002-06-26 1:58 ` Darren New
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