This mouse substitute, which enables primary schoolchildren or those with poor motor control to move the cursor accurately around the computer screen.
Cleanly designed and robustly made, the weight of the unit, together with its non-slip feet, keep it firmly in place on the desk or tray. The solid 2. 5-inch ball provides smooth control and operation but is precisely damped so as not to over-run. There is a very generous length of lead which allows it to be used at some distance from the computer - handy for those in wheelchairs who may not be able to get close.
The version for the Archimedes has three buttons corresponding to the Select, Menu and Adjust buttons on the mouse. The drag function can be operated with one hand. It is locked on simply by holding down the select button. A beep sounds when the drag function is engaged. Versions of the Semerc Roller are also now available for Apple Macintosh and IBM-compatible PCs.
If added control is needed, all three versions of the Roller can be fitted with a clear perspex keyguard.