Date: Fri, 5 Nov 1999 01:13:07 +0000 (GMT) From: Doug Rabson <dfr@nlsystems.com> To: Amancio Hasty <hasty@rah.star-gate.com> Cc: Soren Schmidt <sos@freebsd.dk>, Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>, current@freebsd.org Subject: Re: vga driver and signal Message-ID: <Pine.BSF.4.10.9911050112390.25540-100000@salmon.nlsystems.com> In-Reply-To: <199911041801.KAA46924@rah.star-gate.com>
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On Thu, 4 Nov 1999, Amancio Hasty wrote: > > It seems Kazutaka YOKOTA wrote: > > > > > > AFAIK, not all video cards generate the vertical retrace interrupt. > > > Even worse, some BIOSes have a configuration option which instract the > > > BIOS NOT to assign an IRQ to the PCI video card. > > > > > > I fully agree that the vertical retrace interrupt will be of great > > > value, but I wonder if it is really worth the trouble, because it might > > > be available in only few cards and systems at the end of the day... > > > > > > Well, I may be wrong :-) > > > > Well, sortof :) > > > > The delay caused by the system to process the interrupt and deliver > > the signal etc is unpredictable (well sortof) and is almost certainly > > too long so the window of opportunity will be missed ... > > > > This has been discussed to death many times in the past for the > > mouse pointer updates etc etc... > > > > Let me ask a different question: How does Microsoft's DirectX handle delivery > of vertical retrace interrupt? It doesn't. DX8 might deal with this, I'm not sure. -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 181 442 9037 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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