From:	"Damian Yerrick" <web DOT poison AT pineight DOT 8m DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: problem with far pointers
Date:	Wed, 29 Sep 1999 17:30:39 -0500
Organization:	Rose-Hulman Institute of Technology
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FokkemaDBRA has a selector that points to video RAM.
S/he wants to access video RAM as if it were an array. In
Borland C++, this worked:

> > int far *pointer;

Hans-Bernhard Broeker <broeker AT acp3bf DOT knirsch DOT de> responded:

> There is no such thing as a 'far pointer' in DJGPP. But there are
specialised
> functions (inline assembly, so they should be fast enough for just about
> every application you can come up with), conveniently called the 'far
pointer
> functions'. Look up
>
> farpokeb()
> farpeekb()
> movedata()

Shouldn't movedata() be called farmemmove() or farmemcpy()?

> The one thing you won't get using these functions is use of
> the 'standard' syntax, like 'video_mem[position] = content;'.

Maybe someone could put true far pointer support
(a la Borland) into DJGPP.

> If you insist on that, you must effectively disable
> memory protection using the 'near pointer method'.

And risk overwriting other programs in memory (such as
Windows, DOS, etc.). Overwriting DOS is a Bad Thing.

> See the FAQ for more details about all of this.
> --
> Hans-Bernhard Broeker (broeker AT physik DOT rwth-aachen DOT de)
> Even if all the snow were burnt, ashes would remain.

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