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Date: | Tue, 17 Dec 1996 09:12:08 +0200 (IST) |
From: | Eli Zaretskii <eliz AT is DOT elta DOT co DOT il> |
To: | Shawn Hargreaves <Shawn AT talula DOT demon DOT co DOT uk> |
cc: | djgpp AT delorie DOT com |
Subject: | Re: pmode selectors |
In-Reply-To: | <2V4eiFAhrbtyEwOQ@talula.demon.co.uk> |
Message-ID: | <Pine.SUN.3.91.961217091010.20273J@is> |
MIME-Version: | 1.0 |
On Mon, 16 Dec 1996, Shawn Hargreaves wrote: > _farpokeb(_dos_ds, __tb & 0xFFFFF, 0); > > I'm not 100% sure why it's neccessary to mask of the high bits of the > address, but that's what Eli's FAQ says you should do :-) That's because DPMI host doesn't guarantee that __tb above 20 bits is zeroed. In v1.x, it actually was non-zero. Some library functions would GP Fault if you pass them such addresses. Better be safe than sorry.
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