It’s the “Insert” Key
Did you ever edit some text only to find that the new text you were typing was replacing the text you meant to keep, rather than pushing it to the right?
You typed “Today is a beautiful day” and then decided it should read that today is a really beautiful day. You put your cursor between the words “a” and “beautiful” and typed the word “really.” Instead of what you wanted, you got “Today is a reallyiful day.”
This email is not meant to tell you why you’d ever want to use this convention (you wouldn’t). It’s meant to tell you how to stop it if it ever happens.
The answer: the Insert (INS) key.
On a Windows keyboard, the “Insert” key changes the mode of typing from what I call the “move over” mode to the “replace” mode. The default setting is “move over.” If you inadvertently hit the “Insert” key, you change the mode to “replace.” There is no light, no notice, nothing. You just keep typing and at some point you notice that your current work is replacing your previous work. Hello? Help!
Hit the “Insert” key again to get back to the regular “move over” mode.
Why would anyone ever want this runaway “replace” mode anyway? Hard to imagine. If you wish to replace text, just highlight that specific text and then start typing the new text. It will replace the text you mean to replace, but nothing more.
In fact, the Apple developers have found the key to be completely useless and have eliminated it from their keyboards altogether. (Most likely this key is left over from the old “green screen” days before mice and the ease of highlighting?)
So, if you don’t have this key, you will not be bothered with it. If you have the key and you hit it by mistake, you now know how to fix it.
Have a reallyiful day. Oops!