Topic: How to write a screensaver that makes
May 23, 2019 / By Gawain Question:
I remember awhile back, if you left your computer on for too long, the image could "burn" into your screen. I guess that is why they made screen "savers." But I am wondering if that type of thing is still a problem. Does anyone know? I need to run a program while I am not at home and my computer must be on and not in hibernation or screen saver mode. I have a Compaq laptop that is a few years old. As always, please no silly answers and thanks!!
Dewayne | 3 days ago
Where screensavers came from
Before the advent of color monitors, you could burn the phosphors out of a CRT simply by leaving text displayed. Today, you cannot do that. The original screensavers were programs that blanked out the display. That's all they did. Because of the resource requirements, you didn't find many screensavers in the days when 64K of RAM was the norm.
The ones you did have didn't do much. In the early days of color, the monitors weren't so good and the graphics cards weren't very powerful. So, you might have your screen go to a black on black display or maybe a clock. Even when the 386 was the standard, you usually had to turn the screensaver on manually. You normally did this by typing in a few keystrokes that initiated a batch file. Many users, including the President of Mindconnection, wrote their own screensavers in those days. It was pretty easy to do.
What screensavers are today
Today, screensavers go far beyond black on black displays. The whole idea of a screensaver is to prevent burning a single image into the screen. The likelihood of such an event is remote, but possible, with today's monitors. The typical user doesn't need to worry about damage from not having a screensaver.
It's cheaper just to shut your monitor off, if you are the type who never shuts off the computer. Screensavers do move the images around on the screen, and are like a form of insurance against an exceptionally rare event. You might be more likely to twist your ankle falling off a ladder on the moon than damaging your screen because of no screensaver (providing you have a VGA monitor or better). Screensavers today are almost purely entertainment.
And screensavers are automatic--they initiate on their own, and call subroutines on their own. Screensavers today do everything from scroll some text across your screen to play full-blown movies, complete with sound!
How screensavers affect your system
Plain and simple, they hog resources. The DOS variants (Windows 95/98) suffer much more from screensavers than does an operating system like Windows NT. Prior to Windows 95/98, the situation was especially bad, because of the poor memory management inherent in Windows 3.x.
If your machine never runs slowly, never crashes, and never sees an hour glass, don't worry about your screensaver. However, if you are going to do a resource-intensive operation, you'd probably better disable it. You can try a screensaver and see how it affects your system. You may have resources to spare, and not even notice the drag of the screensaver.
Today's screensavers don't reside in memory. However, the older ones--many of which are still around--do. Those older ones are Terminate and Stay Resident (TSR) applications. This means they always reside in memory, taking up space other applications might want to use. This can cause resource shortages (including CPU resource shortages) that will crash your machine. You'd lose anything not saved to your hard drive. Make sure you don't get a TSR screensaver. If you are buying a new one, it's highly unlikely to be a TSR.
Another way a screensaver can affect your system: it may execute during a critical cycle, knocking out a program that is trying to run, say, overnight.
No not any more and the brurn problem was for CRT monitors not laptop LCDs so you don't have to worry! But if you want there is a setting to turn the display off after----minutes. Try looking in your settings for energy saver -screen-idle -timer
This was a problem with the old CRT style monitors ,I dont believe it is a real issue with newer flat screen monitors, however if you wish to be on the safe side you can always have your screen saver activated.