From:	"Sly" <sly AT aussie DOT net>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: real mode calls pmode
Date:	24 Feb 1997 01:18:52 GMT
Organization:	Sly
Lines:	26
Message-ID:	<01bc21e8$da6654c0$86081ecb@sly>
References:	<5emufu$e7u AT flex DOT uunet DOT pipex DOT com>
NNTP-Posting-Host:	max0ppp04.bne.aussie.net
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

nikki <nikki AT gameboutique DOT co> wrote in article 
> i have an interface driver for some hardware which sadly is written in
old
> 16 bit real mode code. one of the things it requires is that it can call
> part of my code which i'm writing now under djgpp. if i want it to be
able to
> call my function wibble() from within code how exactly should i do this?
> currently, i'm locking all the memory in the same way i would have done
for
> interrupts, then i pass the entry point to my function as
> SEG=(((unsigned int)wibble)>>4) & 0xffff;
> OFF=wib & 0xf
> 

What I think you would have to do would be have a function stub that exists
in conventional memory which is really just a jumping point to the actual
function that exists elsewhere in memory.  Real mode can only use code in
the lower 640kb or something.

That is, if this can be done at all...

-- 

TTFN
Sly (Steve)

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