Almost every computer comes bundled with a mouse. In fact, the mouse has become an ubiquitous symbol of the modern computer industry. In this week’s feature, we’ll look at the history and technology of the mouse, how to choose a mouse to replace the bargain-basement special which came bundled with your computer, and we’ll take a look at alternatives to the traditional mouse.

Mouse History

The mouse as we know it today was conceived by Douglas Englebart at the Stanford Research Institute in the 1960s. Englebart was responsible for a number of new computing concepts, such as hypertext and windowing systems. The original mouse was a boxy wood construction which was popular in test groups because it was easy to handle and more accurate than the trackballs and joysticks which previous researchers had experimented with. Light pens and digitizing tablets were still strong contenders, but the mouse was popular and easy to build.

Sometime in 1979, Steve Jobs took a tour of the Xerox Palo Alto Research Center and saw many of the experimental devices that had been designed there, including many mice. It is no coincidence that the first mass-market personal computer to feature a mouse was the original Apple Macintosh, introduced in 1984. The one-button box proved eminently popular. In fact, Microsoft had shipped the first PC mouse in 1983, but without a windowing system, the mouse was not adopted as an input device by regular users until much later in PC history.

Mouse Operation

Most modern mice work by tracking the movement of a ball in the bottom of the mouse as it rolls against the mousing surface. If you were to open up a mouse and look at the guts, you would see something like the diagram below. Don’t worry, this isn’t freshman biology, so there isn’t any blood.

The mouse ball is in physical contact with two rollers, each of which moves in a different direction. As the mouse is moved across the surface, the data collected from the rollers is sent via the serial port or mouse port to the operating system, which moves the cursor across the screen.

The simplicity of the common mechanical mouse is also its downfall. As the mouse is moved over the surface, the mouse ball picks up dust, hair and other debris. This debris then collects on the rollers, which results in skipping and sticking. Mouse dirt can get so bad that even daily cleaning is barely enough to keep the ball rolling.

There are basically two ways to deal with this problem: clean the mouse, or get a mouse that’s not dependent on traditional technology. There are at least two other types of mice. Optical mice use a low-intensity light source (usually a red LED) on the bottom of the mouse which shines on a special mousepad, which is imprinted with a grid of lines. The mouse reads movement as the light shines on the lines and is reflected (or not) back into the mouse. A competing technology is the Honeywell mouse, which was developed by Honeywell but which is now owned and manufactured by Key Tronic as the Key Tronic Lifetime Mouse. The Honeywell mouse uses two oblique disks to sense movement in the horizontal and vertical directions. Since there is no path for dust to enter the mouse, the mechanism doesn’t need cleaning.

Choosing a New Mouse

If you are a heavy computer user, it probably won’t be long before you’re ready to chuck your mouse in the garbage. The mice that are bundled with many computers today are cheaply made and quickly fall victim to dust contamination. A conscientious cleaning program can keep such a mouse in operating condition until the pads wear off the bottom or the mouse buttons stop working, but eventually it will be time for replacement. Here are some issues to consider.
Cord Length
Don’t pick a mouse with a short cord. Most mouse makers have the sense to put a 6 foot (2 meter) cord on their mice, but some cheapies come with a short cord.
Resolution is the smallest movement that the mouse can distinguish, usually measured in dots per inch. Hence, a 300dpi mouse can detect movements of as little as 1/300th of an inch, while a 525dpi mouse can detect movements of 1/525th of an inch. Most modern mice fall between 350dpi and 600dpi; higher resolutions mean that you can tune the mouse up to a faster speed and get cleaner, higher precision cursor placement.
Number of Buttons
Most PC mice have two buttons, which are required for use with Windows 95, while Mac mice have one button. Some PC mice add a third button between the first two, and others include a gimmicky roller or trackball on top of the mouse. You can decide which is best for you, but if you use applications which are able to use a middle button or a roller, you may find that such a mouse is more useful.
All Mac mice use the ADB (Apple Desktop Bus) interface, while PC mice can use either a 9-pin serial port or a dedicated mouse port. Before buying, take a look on the back of your computer and see what you have available. The serial port is a trapezoidal male connector with 9 pins, while the mouse port is a small round connector with 4 small round holes and a rectangular hole in the middle. The mouse port is frequently referred to as a “PS/2 mouse port”, because it was introduced on the IBM PS/2 computers in 1986.
Like bicycles, you need a mouse that’s sized for you. Don’t select a mouse that requires stretching of the fingers in order to hold on; the result can be hand fatigue. In general, a mouse that seems smaller than you can handle will provide more comfortable use. A good rule of thumb is to choose a mouse that isn’t much wider than your first three fingers held closely together.
Mouse Pad
The quality of the mouse pad can have dramatic effects on the rate of dust contamination and the precision of mouse tracking. Cloth-topped mouse pads can collect dust and will eventually contribute more to dirt in the mouse than no pad at all. The best pads are topped with firm, smooth plastic; they are easily cleaned and allow for smooth tracking. The 3M Precise Mousing Surface has a patterned surface that grabs the mouse ball like a claw and provides super-precise and reliable tracking.

Alternate Mice

As computers have become pervasive in diverse industries, new input devices have been introduced to accomodate situations where mice are not appropriate. Here are a few of those devices:
Digitizing Tablets
Digitizing tablets such as those made by Calcomp and Wacom are able to register pressure as well as position, allowing art and photo retouching applications to use the pressure sensor to control brush width or color intensity. Pictures and drawings can be placed on digitizing tablets and manually rendered into images.
Light Pens
Light pens were popular in the early days of personal computers. They use a light sensor in the tip which is pressed directly against the computer screen, providing 1-to-1 correspondence between the pen location and the cursor location. Light pens are less popular today, but they persist in certain specialized applications such as marking medical images or controlling industrial equipment.
These stubby little controllers go by different names, but they are all basically joysticks which are small enough that they can be embedded between the G, H and B keys on your keyboard. IBM and Toshiba laptops use these pointing devices, and some desktop keyboards have them built-in.
Originally designed for laptops, touchpads for desktop computers are designed as separate devices or built-in to keyboards. Instead of using physical pressure, they actually trigger on the capacitance of human tissue. As a result, they have no moving parts and do not require a stylus.
Touch Screens
A touch screen can either be built-in to a monitor, or added on via a bolt-on screen that goes over the existing monitor screen. The touch screen provides 1-to-1 positioning via a finger, stylus, or similar device. These devices are optimal for kiosks and other environments which must have absolutely no moving parts.
Trackballs actually predate mice; when Douglas Englebart conceived the original mouse, he imagined it as an inverted trackball. Trackballs consist of a smooth sphere ranging in size from golf ball-sized to pool ball-sized inside a cradle with rollers which detect movements of the ball. Trackballs are excellent for space-constrained areas, but require approximately as much maintenance as mice and they are generally harder to master.
Voice Recognition
While voice recognition doesn’t replace a mouse, it can be used to drastically reduce mouse usage by mapping voice commands to specific actions like pulling down menus, opening and closing windows, etc.


The mouse is third on my list of the most important components of your computer system; the first two are the monitor and the keyboard. It’s easy to see why. A bad mouse will provide constant frustration, causing you to miss buttons and menus. A good mouse will track cleanly at all times and require minimal maintenance, if any.