From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank Kotler Subject: Re: video sync timing + softer update Date: Mon, 29 Aug 2005 21:40:47 -0400 Message-ID: <4313B91F.4060206@comcast.net> References: Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-assembly-owner@vger.kernel.org List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Richard Cooper Cc: linux-assembly@vger.kernel.org Richard Cooper wrote: >> Any ideas how I might sync to bit 3 of port 0x3DA, the video card's >> vertical sync signal? I took the liberty or reposting your question to news:alt.lang.asm - more of a warzone than an asm forum, these days, but we were discussing polling loops, and I thought somebody might have some ideas. One response was "I don't bother doing that anymore, vga doesn't need it." Would be nice if it were true, but your experience seems to differ. Another poster (f0dder) posted a link to Kris Heidenstrom's PC timing FAQ, and its info on "emulating a Vertical Retrace Interrupt". All dos stuff, it wouldn't work on Linux as written, of course. But I thought the principles might be useful. However, that's pretty much what you've tried, without success. I didn't realize that the resolution on the timers was so bad. Oh, well... I still think that this approach has as much promise as anything. If the arithmetic doesn't work out... jeez, I'm really reluctant to say anything's "impossible"... ... > http://xerse.nfshost.com/funrestraints/post/000000000016.html > > It's basically version 125, but I made it a "preview" because I'm too > angry now to bother with putting it through the amount of testing I > usually do. Seems to work just fine, though. Great. I haven't looked at 1.26pre yet - barely getting into 1.24 - but it looks like a useful little tool, even if it *won't* synch. Making it a command line option as you've done may be the best you can do. > The last couple of paragraphs in that message are about Softer, the > rest is just ranting. You don't have to read the rants, but if you > like Softer, consider reading them as a way of supporting it's > development. Or some nonsense like that. Okay, I've done my part :) Sorry to hear you're meeting with such frustration. Look on the bright side: Softer's a *hell* of a lot better than no graphics at all (which is what I'm used to). Thanks for sharing it with us! Best, Frank