Date: Wed, 16 Dec 1998 10:08:15 -0000 From: "Bond, Jeffery" <Jeff.Bond@nectech.co.uk> To: "'FreeBSD questions'" <questions@FreeBSD.ORG> Cc: "'robert@namodn.com'" <robert@namodn.com> Subject: RE: doing 1024x768 in X Message-ID: <084DD226F592D211988800A024AC583B02B76C@exchange.nectech.co.uk>
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Trinitron monitors are usually a better breed that your bog-standard monitor, so it should be able to handle higher scan rates than you have set. If he got it cheap then good for him. The horrid flicker is because it is 'interlaced' at 1024x768 (your config file says so). This means that although the monitor is updating at 87Hz, it only does every other scan line on each pass, so your effective Vertical refresh rate is 43Hz. :--( Try rerunning XF86Config (or whatever it's called) and trying some higher rates. BE VERY CAREFUL!!!, you could blow up your monitor if you go to high. Don't blame me if it goes wrong. If you get a screwed up display or a 'whining' noise from your monitor, either turn it off immediately or hit CTRL-ALT-BACKSPACE to quit X. As a guess, leave your V-Sync range at 50-90, but increase your H-Sync rate. That's what really limits monitor performance. For example, if you want 1024x768 at 60Hz (still a bit slow), you need roughly 768x60Hz = 46kHz H sync rate. You currently have the max H-sync at 35.5kHz. To prove my sums work, at 1024x768 at 87Hz interlaced, the monitor only does 768/2 lines per scan, so the H-sync requirement is (768/2) * 87Hz = 33.4kHz. This is very close to the actual 35.5kHz rate. The difference is due to the blank lines at the top and bottom of the picture, and possibly the time taken for the 'flyback'. Good luck, Jeff >My friend is using a Sony Trinitron Multi-Scan HG monitor and a Diamond >Stealth II s220 using X11R6 3.3.2 .. > >He gets a screwy-looking screen when he switches to 1024x768, looks >basically correct 'cept for massive flicker.. > >He bought the monitor for an outrageously low amount at the flea market, >and has no manual. > >Right now it is set to >31.5, 35.15, 35.5; Super VGA, 1024x768 @ 87 Hz interlaced, 800x600 @ 56 Hz > >Perhaps these are the incorrect refresh rates? >If anyone is using this monitor/knows the correct settings, or perhaps >another known problem (?), thanks in advance.. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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