kartooner

From The Straight Dope:

“Q: Why does my com­puter key­board have this “Scroll Lock” key that seems to serve no pur­pose what­so­ever? In 15 years I don’t remem­ber ever push­ing that but­ton. I’m almost scared to touch it –Insane­grey, Lawrence, KS

A: …the main intent of the Scroll Lock key was to allow scrolling of screen text up, down and pre­sum­ably side­ways using the arrow keys in the days before large dis­plays and graph­i­cal scroll bars. You can see where this might have been handy in the DOS era, when screen out­put typ­i­cally was lim­ited to 80 char­ac­ters wide by 25 rows deep. For some types of pro­grams, spread­sheets being the obvi­ous exam­ple, it’s still handy now. In Microsoft Excel, Scroll Lock allows you to scroll a spread­sheet with the arrow keys with­out mov­ing the active cell pointer from the cur­rently high­lighted cell. In Quat­tro Pro, another spread­sheet pro­gram, Scroll Lock works in a sim­i­lar man­ner, although in con­trast to Excel it’s not pos­si­ble to scroll the active cell pointer com­pletely off the screen.“

http://www.straightdope.com/mailbag/mscrolllock.html