Date: Mon, 23 Dec 2002 00:24:00 +0000 From: "clayton rollins" <crollins666@hotmail.com> To: jfm@blueyonder.co.uk Cc: freebsd-newbies@freebsd.org Subject: Re: Vrefresh clocking Message-ID: <F3MvIggcpPxgweE4YLE000094d3@hotmail.com>
next in thread | raw e-mail | index | archive | help
John, First, thanks for your concern... Next, To be a little more specific, it's an IBM 14v monitor(specs list a 76 kHz vrefresh), using an s3 64v+ (86c765 chip) card. The standard vga driver and the s3 trio driver both work with the card. (I should have stated that setup methods don't correctly support this chip, which is obviously supported by bsd drivers. Text mode, partial GUI, and full GUI all end up with very different XF86Config files. [e.g. text mode believes that card is unsupported and will only give a generic vga setup, etc.] Combining different parts of all three gave the final working config. Anyways...) According to the XF86 logs, none of the default modes of the s3 trio will work at a 76kHz vrefresh. Using the vga driver gave me 320x200 at the proper vrefresh. (some modes are also unusable because of the scant 64k video memory this card has.) After plugging in a good multi-sync monitor and adjusting my XF86Config, I re-ran startx, and checked the logs again. To my surprise, three good modes were found with 75-76kHz vrefresh. (using the s3 trio driver) I decided this was an acceptable thing after finding many different companies recommending their users set the vrefresh as low as 73-point-something for this monitor. I also believe that win 98 uses greater ranges than this due to the amount of distortion/flickering I would get in some of their modes (maybe just subjective opinion, though). I'm also going to continue to tinker with a custom modeline to try to get the vrefresh exactly right. (If anyone knows a link or man page which breaks down the math behind this, feel free to shout it out.) Thanks, Clayton >"clayton rollins" <crollins666@hotmail.com> wrote: > > > As a side note, I have generally had no problems using "unsupported" >cards. > >More often the constraint has been from monitor frequency rates. (My last > >one would only work in 320x200 mode with the proper vrefresh. However, I > >knew windows had underclocked the monitor previously, so I didn't think >it > >was too dangerous to go 1 kHz out of spec. I guess I'll see, huh?) > >Um, you wouldn't want to be 1kHz out on vrefresh and I think even the older >VGA monitors would do 640x480. 60Hz vrefresh works for most (uk, not sure >if this applies i13y.), ~85Hz seems flicker free. > >Most modern 'digital' monitors would simply goto standby mode if an attempt >was made to drive it at refresh rates it couldn't accommodate. > >-- >John. _________________________________________________________________ MSN 8: advanced junk mail protection and 3 months FREE*. http://join.msn.com/?page=features/junkmail&xAPID=42&PS=47575&PI=7324&DI=7474&SU= http://www.hotmail.msn.com/cgi-bin/getmsg&HL=1216hotmailtaglines_advancedjmf_3mf To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-newbies" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?F3MvIggcpPxgweE4YLE000094d3>