Mouse evolution. (computer equipment)
by Philip Chien

In this day of WYSIWYG word processors and GUIs, pointing devices are considered requirements instead of options. With all of the different pointing devices available, there's plenty of confusion.

The key difference among pointing devices is how movements are measured. Absolute devices like digitizing tablets have a 1 : 1 correspondence between the pointer's location and the position on the screen. While these devices are excellent for sketching, they require large hand movements for most operations. Most pointing devices use relative motion. When the device is moved, the cursor moves a proportional distance on your screen. Accelerated-movement pointing devices require less hand motion to operate.

As a rule, pointing devices connect to a serial port (serial mouse) or to a special controller card (bus mouse). The primary advantage of a bus mouse is that it doesn't take up one of your serial ports, while a serial mouse costs less because it doesn't need an additional card.

Here are three typical pointing-device upgrades. One of them might be right for you.

Installing a serial mouse. It's extremely simple to install a serial mouse. Just plug it into a spare serial port. Serial mice use standard DB-9 serial connectors. Most will include an adapter for computers with 25-pin serial connectors.

Your device should come with a software driver. The driver should be compatible with Microsoft or Mouse Systems drivers. Follow the directions to install the MOUSE.COM or MOUSE.SYS driver, configure your programs to tell them to use your mouse as an input device, and you're ready to go.

Upgrading a serial mouse to a bus mouse. For many users, the two standard serial ports will be occupied by a mouse and a modem. But what happens if you need to install an additional serial device? It's possible to add more than two serial ports to a computer, but another solution is to convert from a serial to a bus mouse.

Bus mice have slightly better software support than serial mice and are slightly more efficient. A serial-to-bus converter consists of a half-slot controller card with a DB-9 connector. Your pointing device is plugged into the card, which converts the device's signals so they look like those of a bus mouse. Any serial pointing device that looks like a mouse (for example, a trackball) can be attached.

The important things to remember when converting a serial device into a bus device are that you must upgrade your driver to the bus driver supplied with the card and that your programs must be reconfigured to indicate that you're using a bus mouse.

Upgrading to a more sophisticated pointing device. Your computer may have come with an inexpensive mouse. While that mouse may be adequate for simple tasks, you might want a better pointer for fine-resolution desktops, CAD, or drawing applications. If you're using a new pointer with the same physical connector (for example, if you're replacing a serial mouse with another serial device), then you may be tempted just to leave the software drivers alone, particularly if everything appears to be working properly.

This solution works because most pointing devices emulate the Microsoft Mouse, and a new device usually will work with your existing drivers. However, if you don't update your drivers, your software won't recognize the device's special enhancements.

To use your pointing device to its full potential, install the drivers that came with your new device and reconfigure any program that lists your device among its choices. If you have a program that doesn't specifically support your pointing device, it's appropriate to select a generic mouse or pointing device.

One of the simplest upgrades is just to make sure you're using the latest Microsoft driver for your standard mouse. Microsoft drivers come with most Microsoft products. If your mouse does more than the standard Microsoft mouse, check periodically with your manufacturer for upgrades. Most manufacturers operate bulletin boards where these drivers can be downloaded free of charge.

A properly installed pointing device, with software designed to use it to the limit of its capabilities, is an excellent enhancement for any computer. Try out a few pointing devices before deciding which one to use. The variety of options assures that one will be perfect for your work.