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Mail Archives: djgpp/1994/11/11/20:26:04

Date: Fri, 11 Nov 1994 12:20:06 -0500 (EST)
From: Long Doan <ldoan1 AT mason1 DOT gmu DOT edu>
Subject: Re: A question about writing interrupt handler in gcc
To: ALAN L HIGHTOWER <alh AT engr DOT engr DOT uark DOT edu>
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu

On Fri, 11 Nov 1994, ALAN L HIGHTOWER wrote:

> >   You might want to bypass the _..._chain_interrupt because there is a 
> > 'little' overhead involved.
>      How else will I change the vector table?  Using irq7 and not 
> chaining the previous handler locks the system up cold.

  Look at the codes for chaining the isr for int 08 in the fullscreen 
debugger. The instalation routine modifies the IDT, and modifies the ISR to 
JUMP to the original handler (if there is one.) That reduces lotta CPU 
cycles per interrupt.

  Hope that helps,

  Long.

+--------------------------------------------------------+
| Long Doan                        ldoan1 AT mason1 DOT gmu DOT edu |
|                                          ld AT netrix DOT com |
+--------------------------------------------------------+


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