Date: 02 Jul 1998 10:46:00 +0200 From: smoergrd@oslo.geco-prakla.slb.com (Dag-Erling Coidan Smørgrav) To: Nick Hibma <nick.hibma@jrc.it> Cc: FreeBSD hackers mailing list <hackers@FreeBSD.ORG> Subject: Re: Console driver (was: Problems with irq 9(2)?) Message-ID: <rx4af6s4p4n.fsf@oslo.geco-prakla.slb.com> In-Reply-To: Nick Hibma's message of Thu, 2 Jul 1998 09:07:54 %2B0200 (MET DST) References: <Pine.GSO.3.95q.980702085902.16968d-100000@elect8>
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Nick Hibma <nick.hibma@jrc.it> writes: > Isn't there a way to check in which vertical line the graphical > processor is working and then do a tsleep until it arrives at line > number max-2 and _then_ start to do this idle loop? No. The vertical retrace period is the time during which the electron beam is being repositioned from the bottom right to the top left of the screen. Synchronizing with the vertical retrace is not a trivial task, as any demo coder will tell you. However, no VGA board that I know of will exhibit snow while in text mode, so waiting for vertical retrace is not necessary. It should not be removed, though, as older CGA and MDA boards require it; but it could be turned into a kernel option. If you feel very strongly about this, cut'n'paste this article into send-pr and somebody will get around to it. > Or, much better, use an int routine called by the vertical retrace that > is mentioned in the message below. No. Modern graphics adapters do not have that functionality. DES -- Dag-Erling Smørgrav - smoergrd@oslo.geco-prakla.slb.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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