INT 8 isn't a timer interrupt in real-mode on a 386 ?

Article View: comp.sys.ibm.pc.misc

Article #8112

Back to comp.sys.ibm.pc.misc Previous Next

#8112

From: Robert Hartill
Date: Thu, 07 Mar 1991 11:55

24 lines
1599 bytes

i've written a real-mode executive i.e a small OS for a PC,
i want to use INTerrupt 8 to invoke my scheduler,

When i run my executive under the Turbo Debugger (TD and TD386) INT 8
behaves as expected, and my scheduler is invoked,

When i run my executive from the dos command line, the scheduler never
gets invoked,

According to the books i've read,, INT 8 is a timer in real mode,
and a 'double fault' (if i remember correctly) exception in protected mode

A can't be accidentally changing into protected mode, that takes a bit
of code to do the initialisation (yes ?)

HELP !!!

:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::     Robert Hartill, Dept Of Computing Mathematics, UWCC, Cardiff, UK.     ::
::          e-mail : rhl@cm.cf.ac.uk         Fax : 0222 371921               ::
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
There are two kinds of people in the world: those who believe there are two
 kinds of people in the world, and those who don't.   - Ross F. Papprill.
-------------------------------------------------------------------------------

Technical Details

Message-ID: <1991Mar7.115528.23135@cm.cf.ac.uk>

Path: arc1-ca.pugleaf.net!utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!cf-cm!cf-cm!rhl

Show Full Headers

Complete Article Headers

Path: arc1-ca.pugleaf.net!utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!cf-cm!cf-cm!rhl
From: rhl@cf-cm.computing-maths.cardiff.ac.uk (Robert Hartill)
Newsgroups: comp.sys.ibm.pc.misc
Subject: INT 8 isn't a timer interrupt in real-mode on a 386 ?
Message-ID: <1991Mar7.115528.23135@cm.cf.ac.uk>
Date: 7 Mar 91 11:55:28 GMT
Sender: news@cm.cf.ac.uk (USENET News System)
Organization: University of Wales College of Cardiff
Lines: 24