touchpad

A touch sensitive pad used as an input device for computers. Touchpads are often built into notebook computers. The user uses a touchpad by sliding a finger over it.

Touchpads often have buttons positioned so that the user can press them easily while operating the pad.

A contentious thing to put in your laptop computer. OEMs love them because they look all futuristic and add an air of mystique to their product. Quite a few users hate them because they make simple mouse tasks a chore to do.

The touchpad blurb makes a big thing of how you can tap it to simulate a mouse click. Unfortunately you can't push hard to simulate a drag. Some drivers allow you to double-tap to drag-lock, but then how do you doubleclick? The most straightforward way is to hold a mouse button and proceed as normal, but for the uncoordinated (or those with poorly positioned buttons) this is a two-hand operation.

Badly positioned touchpads get in the way while typing. It is possible, especially while touch-typing to snag the touchpad with the base of either thumb. Moving the pointer around is not a bad thing in itself, but when the pad is set to 'tap to click', this can mean moving the cursor, and an irritated typist.

There is no real middle-ground with regards to sensitivity on most touch-pads. After all, the finger is quite a chubby object. That's why most people don't write with finger-paint. This makes it quite difficult to position the thing accurately enough to snag small items (such as the Winamp volume control, or Netscape's toolbar retract buttons). With the sensitivity way down low, the screen can be upwards of three touchpads long. With a mouse or a trackstick, you can just move faster (or harder) and use proportional acceleration. This would just make touchpads even more confusing...

You can't play Quake with them. At all. Try it. (You can, however, play Descent with an Accupoint/trackstick. It's like a tiny analogue joystick...)

Touchpads mostly benefit the OEM by being extremely flat. They have a smaller vertical footprint than an Accupoint, much smaller than a trackball. This leaves more space for a circuit board under the keyboard, or a screen above it. From a user's point of view, they do look cooler, and they don't suffer from Accupoint drift. They don't need new caps, don't get grubby, and don't need their rollers cleaned. But you still can't play quake on them. ;P

Dell has a nice solution in their Inspiron range where the laptop has two sets of buttons, a trackstick and a touchpad. Touchpad haters can configure the touchpad to behave like additional mouse buttons; Trackstick haters can ignore it, or use it as a button. Clever.

Incedentally, Accupoint is a trademark of Toshiba but it has fallen into common use in the same way as Hoover...

Also annoying is the placement of such devices. They sit directly below the keyboard. Many a time have I accidentally brushed my wrist against it and the pointer moves to some completely random place, and my text goes askew. I've also noted a few times when it was impossible that it received direct input from me. This would point to either it receiving presses from the chassis of the notebook being pressed upon, or it making up its input, in response to some other natural phenomenon.

An interesting design point of most touchpads is the way they handle the actually finger-press. If you accidentally put another finger down (common occurrance, believe me), the pointer will jump. The distance is determined by the midpoint of the line between your fingers.

This fact can be used for a temporary diversion, I've found. You touch with one finger, then place the other down, then lift the first finger. The pointer will "walk" across the screen this way. Not very useful, but when you've been on the phone for 15 minutes listening to silence, anything goes.