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Re: [Wlug] Wlug Digest, Vol 70, Issue 17

by Steven Greenberg

The issue with 60 Hz and the LCD was not flicker. I mentioned visual defects. I meant things like missing pixels. I had to use the analog connection because that was all that was available on the PC that I had just bought. I just looked at the setting now to see if I had really chosen 120 Hz which is still a harmonic of 60Hz. Unfortunately for looking at the setting, I moved three years ago from the house where the office had fluorescent lights. When I set up my computer again in the new house, I must have somehow gone back to the default 60 Hz. There are no fluorescent lights around and there are none of the visual defects I saw in the other house. When I brought my unit back to Fry's electronics they had no such problem in the store from the ceiling lights which were a good 15 or more feet away. They gave me a replacement anyway just to keep me happy. I had not even suspected fluorescent lights at that point. When I got the replacement home, it had the same problem as the first one. I was about to give up on Samsung in disgust when I asked around at work if anybody could figure out the problem. Our computer hardware support person mentioned the fluorescent light idea. I went home, changed the frequency and the problems disappeared. The fluorescent lights in my home office were probably only 4 feet from the LCD. The cause of the problem might have been something completely different, but I cannot come up with another explanation that fits the observations. Maybe I had sympathetic 60 Hz fluctuations from my neighbor's ham radio. Whatever was the cause, getting away from 60Hz seemed to be the solution. /Steve -- Steven Greenberg Email: steve(a)ssgreenberg.name 251 Holland Rd. Phone: (774)241-0095 Fiskdale, Massachusetts 01518-1231 Web: http://www.ssgreenberg.name Other Email: s.greenberg(a)ieee.org ssg(a)alum.mit.edu

Aug. 20, 2009

Re: [Wlug] Here I am begging again.

by John Stoffel

Ken> I have not been making the meetings. That does not mean my SUN Ken> ULTRA1 running Aurora Linux can no longer create 'interesting' Ken> problems. This time the second SUN ULTRA running Gentoo is in Ken> cahoots. Ken> I have a new SAMSUNG SyncMaster flat screen monitor. I have Ken> attached this monitor via a Belkin SUN adapter to my ULTRA1's. This is the 13W3 to VGA (HDB15) analog connector? Not the HDMI connector on the monitor? I've got a ton of Samsung 204Bs at work and they're nice to work on. Ken> It does not work!! The monitor flashes a little square window Ken> saying something about "Not optimum mode". It feels that it has Ken> not been configured correctly. The buttons on the right of the Ken> monitor, which are there to set it up, also do not work with the Ken> SUN's is attached. Ken> The monitor works fine with PC type machinery. The Belkin worked Ken> fine with a regular old tube monitor. (I have not dug out the Ken> old monitor to check whether it still works. I suspect it does.) Ken> Anybody have any ideas? Hmmm... if it was running Solaris I'd say take a look at the m64config command, but that's for Ultra 5/10 boxes. Basically, I think you need to force X to use a certain configuration. What does 'xrandr -query' say? Anything useful? Try editing your /etc/X11/xorg.conf to have a section like this, though you'll need to change the DEVICE from my old Matrox to whatever the Sun is really using. Section "Monitor" Identifier "Samsung LCD" HorizSync 60 EndSection Section "Screen" Identifier "Default Screen" Device "Matrox Graphics, Inc. MGA G400/G450" Monitor "Samsung LCD" DefaultDepth 24 SubSection "Display" Depth 1 Modes "1280x1024" EndSubSection SubSection "Display" Depth 4 Modes "1280x1024" EndSubSection SubSection "Display" Depth 8 Modes "1280x1024" EndSubSection SubSection "Display" Depth 15 Modes "1280x1024" EndSubSection SubSection "Display" Depth 16 Modes "1280x1024" EndSubSection SubSection "Display" Depth 24 Modes "1280x1024" EndSubSection EndSection

Aug. 20, 2009

Re: [Wlug] Here I am begging again.

by jrm8005＠gmail.com

> I thought the whole big deal about refresh rates on LCDs is that they > actually have a florescent light in the back of them that shines through the > liquid crystal. > > I've noticed that it's less of a big deal with LCDs though... I have an LCD that uses LED backlighting, but it still has a refresh rate. > > -Randall > > > On Thu, Aug 20, 2009 at 3:14 PM, Jim Dibb <jimdibb(a)gmail.com> wrote: > >> I don't think refresh rate applies to LCDs in the 'flicker' sense at all. >> Refresh is for scanning (crt) displays that have to keep scanning or the >> phosphor pixels fade out. >> >> LCD pixels are 'ON' or 'OFF' they don't fade out between refreshes. >> >> I believe the new hype on the 120 or 240 Hz refresh on big lcd tvs is all >> about motion interpolation, not flicker. Since the source video framerate >> is still only 24 or 30 Hz. >> >> >> On Thu, Aug 20, 2009 at 3:04 PM, Richard Klein <richspk(a)gmail.com> wrote: >> >>> On Thu, Aug 20, 2009 at 2:32 PM, Steven Greenberg<steve(a)ssgreenberg.name> >>> wrote: >>> > I have a Samsung SyncMaster 204B, but it is on a Windows PC. >>> > >>> > As for the frequency, 60 Hz is not good in close proximity to >>> > fluorescent lights. >>> > >>> > I had a lot of visual defects in two different units, until I changed >>> > to 120 Hz(I think). >>> >>> That's true with CRTs. I think it may be less important with LCDs. I >>> have a SyncMaster 213T at home, and if you use the DVI port you have >>> no choice but 60 Hz. I've never noticed any flicker from it. Most of >>> the lighting in my apartment is CFLs. >>> >>> -- >>> Rich >>> Sent from Marlborough, MA, United States >>> _______________________________________________ >>> Wlug mailing list >>> Wlug(a)mail.wlug.org >>> http://mail.wlug.org/mailman/listinfo/wlug >>> >> >> >> _______________________________________________ >> Wlug mailing list >> Wlug(a)mail.wlug.org >> http://mail.wlug.org/mailman/listinfo/wlug >> >>

Aug. 20, 2009

Re: [Wlug] Here I am begging again.

by Randall Mason

http://solutions.3m.com/wps/portal/3M/en_US/Vikuiti1/BrandProducts/secondar… And click on Navigation and choose "Backlight". -Randall On Thu, Aug 20, 2009 at 3:20 PM, Randall Mason <clashthebunny(a)gmail.com>wrote: > I thought the whole big deal about refresh rates on LCDs is that they > actually have a florescent light in the back of them that shines through the > liquid crystal. > > I've noticed that it's less of a big deal with LCDs though... > > -Randall > > > > On Thu, Aug 20, 2009 at 3:14 PM, Jim Dibb <jimdibb(a)gmail.com> wrote: > >> I don't think refresh rate applies to LCDs in the 'flicker' sense at all. >> Refresh is for scanning (crt) displays that have to keep scanning or the >> phosphor pixels fade out. >> >> LCD pixels are 'ON' or 'OFF' they don't fade out between refreshes. >> >> I believe the new hype on the 120 or 240 Hz refresh on big lcd tvs is all >> about motion interpolation, not flicker. Since the source video framerate >> is still only 24 or 30 Hz. >> >> >> On Thu, Aug 20, 2009 at 3:04 PM, Richard Klein <richspk(a)gmail.com> wrote: >> >>> On Thu, Aug 20, 2009 at 2:32 PM, Steven Greenberg<steve(a)ssgreenberg.name> >>> wrote: >>> > I have a Samsung SyncMaster 204B, but it is on a Windows PC. >>> > >>> > As for the frequency, 60 Hz is not good in close proximity to >>> > fluorescent lights. >>> > >>> > I had a lot of visual defects in two different units, until I changed >>> > to 120 Hz(I think). >>> >>> That's true with CRTs. I think it may be less important with LCDs. I >>> have a SyncMaster 213T at home, and if you use the DVI port you have >>> no choice but 60 Hz. I've never noticed any flicker from it. Most of >>> the lighting in my apartment is CFLs. >>> >>> -- >>> Rich >>> Sent from Marlborough, MA, United States >>> _______________________________________________ >>> Wlug mailing list >>> Wlug(a)mail.wlug.org >>> http://mail.wlug.org/mailman/listinfo/wlug >>> >> >> >> _______________________________________________ >> Wlug mailing list >> Wlug(a)mail.wlug.org >> http://mail.wlug.org/mailman/listinfo/wlug >> >> >

Aug. 20, 2009

Re: [Wlug] Here I am begging again.

by Randall Mason

I thought the whole big deal about refresh rates on LCDs is that they actually have a florescent light in the back of them that shines through the liquid crystal. I've noticed that it's less of a big deal with LCDs though... -Randall On Thu, Aug 20, 2009 at 3:14 PM, Jim Dibb <jimdibb(a)gmail.com> wrote: > I don't think refresh rate applies to LCDs in the 'flicker' sense at all. > Refresh is for scanning (crt) displays that have to keep scanning or the > phosphor pixels fade out. > > LCD pixels are 'ON' or 'OFF' they don't fade out between refreshes. > > I believe the new hype on the 120 or 240 Hz refresh on big lcd tvs is all > about motion interpolation, not flicker. Since the source video framerate > is still only 24 or 30 Hz. > > > On Thu, Aug 20, 2009 at 3:04 PM, Richard Klein <richspk(a)gmail.com> wrote: > >> On Thu, Aug 20, 2009 at 2:32 PM, Steven Greenberg<steve(a)ssgreenberg.name> >> wrote: >> > I have a Samsung SyncMaster 204B, but it is on a Windows PC. >> > >> > As for the frequency, 60 Hz is not good in close proximity to >> > fluorescent lights. >> > >> > I had a lot of visual defects in two different units, until I changed >> > to 120 Hz(I think). >> >> That's true with CRTs. I think it may be less important with LCDs. I >> have a SyncMaster 213T at home, and if you use the DVI port you have >> no choice but 60 Hz. I've never noticed any flicker from it. Most of >> the lighting in my apartment is CFLs. >> >> -- >> Rich >> Sent from Marlborough, MA, United States >> _______________________________________________ >> Wlug mailing list >> Wlug(a)mail.wlug.org >> http://mail.wlug.org/mailman/listinfo/wlug >> > > > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug > >

Aug. 20, 2009

Re: [Wlug] Here I am begging again.

by jrm8005＠gmail.com

> I don't think refresh rate applies to LCDs in the 'flicker' sense at all. > Refresh is for scanning (crt) displays that have to keep scanning or the > phosphor pixels fade out. > > LCD pixels are 'ON' or 'OFF' they don't fade out between refreshes. > > I believe the new hype on the 120 or 240 Hz refresh on big lcd tvs is all > about motion interpolation, not flicker. Since the source video framerate > is still only 24 or 30 Hz. Interesting! > > On Thu, Aug 20, 2009 at 3:04 PM, Richard Klein <richspk(a)gmail.com> wrote: > >> On Thu, Aug 20, 2009 at 2:32 PM, Steven Greenberg<steve(a)ssgreenberg.name> >> wrote: >> > I have a Samsung SyncMaster 204B, but it is on a Windows PC. >> > >> > As for the frequency, 60 Hz is not good in close proximity to >> > fluorescent lights. >> > >> > I had a lot of visual defects in two different units, until I changed >> > to 120 Hz(I think). >> >> That's true with CRTs. I think it may be less important with LCDs. I >> have a SyncMaster 213T at home, and if you use the DVI port you have >> no choice but 60 Hz. I've never noticed any flicker from it. Most of >> the lighting in my apartment is CFLs. >> >> -- >> Rich >> Sent from Marlborough, MA, United States >> _______________________________________________ >> Wlug mailing list >> Wlug(a)mail.wlug.org >> http://mail.wlug.org/mailman/listinfo/wlug >>

Aug. 20, 2009

Re: [Wlug] Here I am begging again.

by Jim Dibb

I don't think refresh rate applies to LCDs in the 'flicker' sense at all. Refresh is for scanning (crt) displays that have to keep scanning or the phosphor pixels fade out. LCD pixels are 'ON' or 'OFF' they don't fade out between refreshes. I believe the new hype on the 120 or 240 Hz refresh on big lcd tvs is all about motion interpolation, not flicker. Since the source video framerate is still only 24 or 30 Hz. On Thu, Aug 20, 2009 at 3:04 PM, Richard Klein <richspk(a)gmail.com> wrote: > On Thu, Aug 20, 2009 at 2:32 PM, Steven Greenberg<steve(a)ssgreenberg.name> > wrote: > > I have a Samsung SyncMaster 204B, but it is on a Windows PC. > > > > As for the frequency, 60 Hz is not good in close proximity to > > fluorescent lights. > > > > I had a lot of visual defects in two different units, until I changed > > to 120 Hz(I think). > > That's true with CRTs. I think it may be less important with LCDs. I > have a SyncMaster 213T at home, and if you use the DVI port you have > no choice but 60 Hz. I've never noticed any flicker from it. Most of > the lighting in my apartment is CFLs. > > -- > Rich > Sent from Marlborough, MA, United States > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug >

Aug. 20, 2009

Re: [Wlug] Here I am begging again.

by jrm8005＠gmail.com

> On Thu, Aug 20, 2009 at 2:32 PM, Steven Greenberg<steve(a)ssgreenberg.name> wrote: >> I have a Samsung SyncMaster 204B, but it is on a Windows PC. >> >> As for the frequency, 60 Hz is not good in close proximity to >> fluorescent lights. >> >> I had a lot of visual defects in two different units, until I changed >> to 120 Hz(I think). > > That's true with CRTs. I think it may be less important with LCDs. I > have a SyncMaster 213T at home, and if you use the DVI port you have > no choice but 60 Hz. I've never noticed any flicker from it. Most of > the lighting in my apartment is CFLs. The only reason CRT flicker bothers the eye is because of the time it takes the electron guns to return to the top of the screen. Since LCDs don't have an electron gun (I think the whole screen refreshes at once), the flicker is not really noticeable since there is no waiting for the gun to reposition. > > -- > Rich > Sent from Marlborough, MA, United States > _______________________________________________ > Wlug mailing list > Wlug(a)mail.wlug.org > http://mail.wlug.org/mailman/listinfo/wlug

Aug. 20, 2009

Re: [Wlug] Here I am begging again.

by Richard Klein

On Thu, Aug 20, 2009 at 2:32 PM, Steven Greenberg<steve(a)ssgreenberg.name> wrote: > I have a Samsung SyncMaster 204B, but it is on a Windows PC. > > As for the frequency, 60 Hz is not good in close proximity to > fluorescent lights. > > I had a lot of visual defects in two different units, until I changed > to 120 Hz(I think). That's true with CRTs. I think it may be less important with LCDs. I have a SyncMaster 213T at home, and if you use the DVI port you have no choice but 60 Hz. I've never noticed any flicker from it. Most of the lighting in my apartment is CFLs. -- Rich Sent from Marlborough, MA, United States

Aug. 20, 2009

getting rid of some monitors

by Jared Greenwald

I apologize in advance for spamming the list with my want ad. I need to get rid of some CRT monitors and am wondering if anyone on the list would be interested. They are as follows... 1x Gateway Vivitron (circa '95) 17" 1x Compaq MV940 19" 2x Digital re-branded Trinitron 21" (matched pair) The 19" and 21" monitors can each run at 1600x1200 and the 21s have dual input, which is nice. I used the 21s in a TwinView setup on my main Ubuntu-based workstation at home for years until I got a LCD last Christmas. I have power/video cables for all of them, so they are ready to roll. I had them up on craigslist to try and sell them, but haven't gotten any hits and it's just time to clear out the space. The catch is that you would need to come pick them up from me in Uxbridge. Please respond to me privately so we don't spam the list. Thanks, Jared Greenwald

Aug. 20, 2009