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Mail Archives: djgpp/1997/12/15/21:46:18

From: "Tony O'Bryan" <aho450s AT nic DOT smsu DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Geting 8x8 text from rom?
Date: Mon, 15 Dec 1997 17:57:59 -0600
Organization: Southwest Missouri State University
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Message-ID: <3495C407.1562@nic.smsu.edu>
References: <34938c5f DOT 0 AT pusher DOT student DOT adelaide DOT edu DOT au> <34951A01 DOT 5C6864E3 AT nm3 DOT ktu DOT lt>
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To: djgpp AT delorie DOT com
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Martynas Kunigelis wrote:

> > I would like to know how I would use farnspeekb for the following address.
> > 0xF000FA6E which contains the 8x8 font for mode 13h in rom. The only
>   ^^^^^^^^^^
> 
> Wrong! It's F000:FA6E in 8086 segmented addressing notation. Please
> note, that this is _very_ different from 0xF000FA6E. The linear address
> for F000:FA6E is 0xFFA6E.

There is no reason to get hyper on him, especially since he is correct
for the platform he came from.  Turbo C required far pointers to specify
a segment:offset address as a single long pointer.  Hence A000:0000 was
addressed as:

unsigned char far *Screen = (unsigned char far *)0xa0000000;

And the font ROM would be addressed as (assuming the address is
F000:FA6E):

unsigned char far *Rom = (unsigned char far *)0xf000fa6e;

You are correct about the protected mode linear address, and he was
correct about the real mode Borlandism.

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