Once upon a time, there was a simple, text-based operating system called DOS. Most people don’t realize, but DOS was the term was for the Apple 2 series of computers.
Then, along came the IBM PC and the “Microsoft DOS” (MS-DOS) disk operating sytem that many of us came to know and love.
One of the really neat features of MS-DOS was really part of its keyboard facilities — IBM had put a “Prnt Scrn” key on the keyboard, and MS-DOS knew what to do with that.
Just press Prnt Scrn, and you got a dump of the monitor screen’s contents to the printer. Oh, by the way, printers in those days were also text handlers. To print an “E,” the program sent the 8-bit value that meant E to the printer, and the built-in smarts on the printer knew how to print the E.
Monitor resolution was similarly lousy — you could actually see each of the dots that made up an E, without trying hard.
And then, along came Windows. Windows took an entirely different view on the world. No longer was this a text- or character-oriented world, this was now a graphical world. The Prnt Scrn key was one of the first things to go…
Under Windows, then and now, if you press the Prnt Scrn key, you actually make copy of the screen into a part of memory that Windows calls the “Windows Clipboard.” This copy includes all the dots and colors you are displaying — if you use 800×600 resolution and 256 colors, then the copy includes all 800×600 (480,000) pixels and the corresponding information on their colors. If you use 1600×1050, then it includes all 1,680,000 pixels and their color information. And, it’s all stored there as an image.
So, how do you actually print the screen when you are running Windows? The expensive way is to purchase a special screen-print utility. This is a program that intercepts that keypress and actually grabs the data itself. Screen-print utilities usually also have some other features, such as the ability to save the image to the disk.
For the more frugal user, we can still do both of these tasks. To print the screen, press the Prnt Scrn button to put the image into memory. Then, open up the built-in Windows application called “WordPad” and paste the image into it (Edit / Paste).
If you are running Windows XP, Wordpad is no longer on the Start / All Programs / Accessories menu, but you can put it there. It is found as C:\Windows\Write.exe (if you are showing file extensions, as you should), if not, it shows as C:\Windows\Write. Once you paste the image into Wordpad, you can save or print it.
You can similarly paste it into Paint, or any other image editor, or into any other program that will accept pasted images. In this manner, you can paste into Microsoft Word, OpenOffice.org’s Write, WordPerfect and other programs.
Special Tip: PrntScrn takes a picture of the whole screen. If you hold down the Alt button while you press PrntScrn — it will copy only the active window!