Kensington Expert Mouse Version 4.0 Trackball 2-Button Serial DB9 PC Compatible

Kensington Expert Mouse Version 4.0 Trackball 2-Button Serial DB9 PC Compatible

The Kensington Expert Mouse Version 4.0 is a programmable 2-button trackball designed for IBM PC and compatible systems. Unlike a conventional mouse, the trackball uses a large stationary ball that the user rolls with their fingers or palm to control the cursor, keeping the device itself fixed on the desk. Kensington marketed this model as a precision alternative to standard mice, aimed at users who wanted reduced wrist movement and greater cursor control.

Specifications & What's Included

• Brand: Kensington Microware Limited
• Model: Expert Mouse, Version 4.0
• Part Number: 32930216EB
• FCC ID: GV364201
• Buttons: 2
• Programmable: Yes
• Interface: Serial (DB9 female 9-pin connector)
• Compatible with: IBM PC and compatibles
• Country of Manufacture: USA (Made in U.S.A.)
• Color: Beige/Ivory
• Includes: Trackball unit with attached serial cable — no software or documentation

Applications

The Kensington Expert Mouse series dates from the late 1980s through the 1990s, a period when serial (RS-232) port connections were the standard interface for pointing devices before PS/2 and USB became ubiquitous. This Version 4.0 was designed for DOS and early Windows environments running on IBM PC/AT-class and compatible machines. It connected via a 9-pin DB9 serial port, found on virtually all PCs of the era. Trackballs of this type were popular in CAD, graphic design, and desktop publishing workstations where precise cursor placement mattered more than rapid movement. Today, units like this are sought by collectors of vintage computing peripherals, retro PC enthusiasts, and operators of legacy systems that still require serial input devices.