Date: Fri, 26 Jul 1996 12:41:04 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: "Alaric B. Williams" <alaric AT abwillms DOT demon DOT co DOT uk>
Cc: djgpp AT delorie DOT com
Subject: Re: preemptive multitasking for dj
In-Reply-To: <838120311.10346.1@abwillms.demon.co.uk>
Message-Id: <Pine.SUN.3.91.960726123734.19397D-100000@is>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII


On Tue, 23 Jul 1996, Alaric B. Williams wrote:

> Thing is, I'm not sure how many RTCs will still generate this int, and
> I've heard that some BIOSes use it internally; in other words, messing
> with it can interfere with low level BIOS things like power
> management!
> 
> Any verification of that???

All BIOSes I know of use the RTC (for some time-related functions of Int 
15h), but if you chain to the previous interrupt handler, you can do no 
harm at all.  The initialization code should check the frequency of the 
RTC timer interrupt and arrange for chaining to the old handler with that 
frequency.