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Index > DOS > Does BIOS use in/out port commands?

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lilainst



Joined: 29 Jul 2004
Posts: 11
lilainst
I think the DOS interrupt is on the high level, BIOS interrupt is lower, and I/O command is the lowest. So all I/O interruptions (include BIOS interrupts) will finally use in/out port commands, am I right? Is it possible to debug or trace into the BIOS interrupt handlers?
Post 28 Mar 2006, 13:58
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Matrix



Joined: 04 Sep 2004
Posts: 1171
Location: Overflow
Matrix
hmm,
dos is slower, that is sure, if you use some dos function, instead of bios function, but if you have to talk to hardware, then you must use port commands, no other way to do it.

you can trace real time with softice. can trace interrrupts i remember.
works under win98, and dos well.

sure, you will see many outs and ins.

the reason these hardware level functions are not commonly used, is compatibility, 10 computers may have 10 different chipsets...

remember you have motherboard drivers on your windows too, and video card drivers, etc.
Post 30 Mar 2006, 18:55
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TDCNL



Joined: 25 Jan 2006
Posts: 56
TDCNL
But theres always a standard way to do all things with IN and OUT no? Or does DOS sort it out for each chipset Question

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Post 09 Apr 2006, 19:36
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shaolin007



Joined: 03 Sep 2004
Posts: 65
shaolin007
From what I have read, there is some standardization or backward compatibility with embedded chips. But, it is best to use BIOS level interrupts to do this except in video services and few others.
Post 12 Apr 2006, 14:13
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vid
Verbosity in development


Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia
vid
some things are standardized and can be done in way you described, other don't
Post 12 Apr 2006, 14:16
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TDCNL



Joined: 25 Jan 2006
Posts: 56
TDCNL
ty guys, that explained it Very Happy

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Post 14 Apr 2006, 08:15
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