latornell@MECH.UBC.CA (Doug Latornell) (02/08/90)
There have been some comments recently about potential damage resulting from the use of screen savers that change the screen to all black. Could someone please explain this? I thought the idea of a screen saver was to preserve the phosphorous by displaying nothing when the machine is not in use. I've been using Moshe Braner's (sp?) Idle 1.2 for about 2 years now on a 1040ST with a SM124 (monchrome) monitor and have noticed no ill effects. Am I slowly killing my monitor?? Doug Latornell latornell@mech.ubc.ca
hcj@lzsc.ATT.COM (HC Johnson) (02/10/90)
In article <271*latornell@mech.ubc.ca>, latornell@MECH.UBC.CA (Doug Latornell) writes: > There have been some comments recently about potential damage resulting from > the use of screen savers that change the screen to all black. Could someone > please explain this? I thought the idea of a screen saver was to preserve The problem is how all black is obtained. The all black screen saver selects 'external sync' for the video. (An artifact of trying to work with a GENLOCK). Since there is no sync coming in on external, the screen goes blank. The problem is that the monitor expected sync pulses to keep its flyback oscillator in time. If a monitor tends to free run at a frequency too far removed from the missing sync, the fly-back and the driver chips may overload and overheat. Oscillators are really strange things. Also, with no sync, their is really no output signal (video information) either. This can cause the bias on the video amplifiers to get to a point where, again, they can overheat. My old Mono, seems not to care about all of this. My new Mono, hasn't complained (died) yet, but Atari did post a warning to look out. My old color, also seems not to care, but I don't run it often, or blank it for long times. Howard C. Johnson ATT Bell Labs =====NEW address==== att!lzsc!hcj hcj@lzsc.att.com
mark@ccvr1.ncsu.edu (Mark Boyd) (02/10/90)
Moshe Braner's Idle 1.2 does not blank the screen by removing signals from the monitor. It displays a black screen using the memory below the default video memory. If that area is in use, it just does reverse video on the screen. It will NOT hurt your monitor. I've used it for years and I've examined the code in detail. Moshe writes good code! Mark Boyd Univ of North Carolina Asheville boyd@erma.unca
bwhite@oucsace.cs.OHIOU.EDU (Bill White) (02/16/90)
In article <1990Feb10.153630.29627@ncsuvx.ncsu.edu>, mark@ccvr1.ncsu.edu (Mark Boyd) writes: > Moshe Braner's Idle 1.2 does not blank the screen by removing signals > from the monitor. It displays a black screen using the memory below the > default video memory. If that area is in use, it just does reverse video > on the screen. It will NOT hurt your monitor. I've used it for years and > I've examined the code in detail. Moshe writes good code! > Out of curiosity, wouldn't it be simpler just to set all the colors to zero? Sure, you'd need a whole 32 bytes to store the original colors in, but I'm sure you could find that much somewhere. It seems to me that just reversing the screen video would keep a particular PATTERN from burning in, but wouldn't stop contribution to overall monitor dimming. By the same token, switching to a blank area won't help if you're background color is white (or bright color) for the same reason. I haven't found any screen saver that I've liked yet. The Fuji one sounds interesting but sort of defeats the whole purpose of a screen saver (ie prevent a pattern from burning into the monitor, and prevent the monitor from losing brightness). I have a PD one which kicks into effect after no input for so long, but it tends to cause programs to crash (or stop, more often, including file transfer programs!) If anyone would be willing to send me the basic code for one (I don't have the time these days to write daemons), and your list of complaints about existing ones, I'd try my hand at writing one, but no doubt it'd be bug-filled as well. Mind you, I'm not knocking anyone's code; I'm just mentioning my own views about this subject. As for killing the V-sync, I've got a NEC MultiSync 3D, and if the Vsync drops, the monitor screeches like it's being tortured! Bill White bwhite@oucsace.cs.ohiou.edu ...!att!oucsace.cs.ohiou.edu!bwhite
roland@cochise.pcs.com (Roland Rambau) (02/20/90)
bwhite@oucsace.cs.OHIOU.EDU (Bill White) writes:
->Out of curiosity, wouldn't it be simpler just to set all the colors to zero?
This does not work in monochrome mode. You can't set both colors to black
- the systems probably recognizes only 1 bit of the color table ( standard
vs. inverted ).
Roland Rambau
rra@cochise.pcs.com, {unido|pyramid}!pcsbst!rra, 2:507/414.2.fidonet rehrauer@apollo.HP.COM (Steve Rehrauer) (02/23/90)
In article <1990Feb20.085117.15757@pcsbst.pcs.com> roland@cochise.pcs.com (Roland Rambau) writes: >bwhite@oucsace.cs.OHIOU.EDU (Bill White) writes: >->Out of curiosity, wouldn't it be simpler just to set all the colors to zero? > >This does not work in monochrome mode. You can't set both colors to black >- the systems probably recognizes only 1 bit of the color table ( standard >vs. inverted ). Note that, from what has been said here about it, the TT's 640x400 'monochrome' display mode really does pay attention to both color 0 and color 1. (I believe the mode is actually called 'duochrome' on the TT, ugg.) Such a blanker would work on the TT, at least for the 3 ST resolutions. -- >>"Aaiiyeeee! Death from above!"<< | Steve Rehrauer, rehrauer@apollo.hp.com "Flee, lest we be trod upon!" | The Apollo System Division of H.P.