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Mail Archives: djgpp/1997/09/29/21:24:43

Date: Mon, 29 Sep 1997 18:22:12 -0700 (PDT)
Message-Id: <199709300122.SAA20962@adit.ap.net>
Mime-Version: 1.0
To: Georg DOT Kolling AT t-online DOT de (Georg Kolling), blizzar AT hem1 DOT passagen DOT se
From: Nate Eldredge <eldredge AT ap DOT net>
Subject: Re: BIOS call from interrupt?
Cc: djgpp AT delorie DOT com

At 11:04  9/29/1997 DST, Georg Kolling wrote:
>Peter Palotas schrieb:
>> BIOS is slower, but that wouldn't be all that relevant in ex. a GUI. But
>> how does using BIOS functions affect the portability of the program to
>> Linux? I can't imagine that being a great idea!?
>>
>It doesn't affect the portability at all. The BIOS function set is the same on
>any IBM compatible PC no matter which OS you're using (At least functionality 
>is the same, not hte code) . It is stored in an (EP)ROM on the mainboard 
>of a PC. The BIOS functions are just used for low level hardware stuff such 
>as reading/writing a disk sector, using COM and LPT ports, receiving
>keyboard input and so on. These functions do not depend on the OS
>that is running on the computer.
You are correct in that the BIOS stays the same.  But the topic was in
regard to using the BIOS to read an ascii code from the keyboard inside an
interrupt handler. Under Linux, all bets are off. Linux does not use the
BIOS at all, and IIRC, does not even map it into memory. (Or if it does, it
puts it somewhere weird...) Not to mention that you can't hook interrupts or
read the I/O ports directly under Linux... I would say, if you're going to
do anything remotely hardware-specific, forget about portability to Linux.

Nate Eldredge
eldredge AT ap DOT net



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