Before there were laser and optical mice, there was the computer ball mouse, also known as the trackball or rollerball! Those born in the 1990s will fondly remember these computer mice because they had a ball in it, underneath the mouse, which naughty kids would take from school computers.
If you ever took out the ball from a computer ball mouse you probably thought it was just a rubber ball, but actually the ball had another ball inside it made of steel alloy which is a cool fun fact.
Trackballs such as the Perixx PERIMICE-517 have made a bit of a comeback, bouncing back stronger than ever and with smart features! The Perixx PERIMICE-517 has the ball on the side rather than on top or down below like some other computer mice trackballs.
Computer mice trackballs do work slightly different to regular mice. Instead of sliding the mouse on a desk to move the cursor pointer on the screen, you spin the optically tracked ball inside the Perixx PERIMICE-517 with your right thumb. The location of the trackball is comfortable but linear movement is not as precise as with a regular mouse like the PERIMICE 803.
If you are someone with thumb issues, a trackball mouse like the Perixx PERIMICE-517 won't be suited because of the amount of flexing your thumb has to do especially when scrolling downwards.
Aside from the standard left click and right click buttons, the Perixx PERIMICE-517 has a rubber texture scroll wheel and four dedicated buttons. The buttons above the scroll wheel are two dpi switch buttons to adjust sensitivity speed of the trackball between 400 dpi and 1000 dpi.
The other two buttons on the far top left corner of the mouse  are dedicated back and forward buttons that you operate with the index finger while your hand is resting on the mouse.
The Perixx PERIMICE-517 rollerball mouse measures 13cm long (from top to base), 10cm wide (from side to side) and 4.5cm high (from top to bottom) so it can fit small hands comfortably without having to lift the hand to reach the back and forward buttons.
Total weight is 125 grams while the rubberized USB cable is 1.8 meters long. The USB cable has a USB 2.0 connector that is backward compatible with USB 1.1 so you can connect the Perixx PERIMICE-517 trackball mouse in to the USB 1.1 port of an old computer like the Dell Dimension D-4400.
The D-4400 stock operating system is Windows XP Home Edition so the Perixx PERIMICE-517 mouse would work fine on an old computer like the D-4400 because this mouse is compatible with Windows ME, Windows 2000, Windows XP, Windows Vista and newer versions of Windows (7, 8 and 10).
The body of the Perixx PERIMICE-517 computer mouse with ball on the side is made of polycarbonate (PC) and ABS so the mouse has a feel like silicone that is soft to the touch.
The ball can be also removed from the body of the Perixx PERIMICE-517 for cleaning. Simply take a pencil or other thin object and insert it in the small hole on the bottom of the mouse. Press in and the ball will pop out.
When cleaning, you should clean the "cup" that holds the ball but be very careful not to break off the "red" beads because losing just one of these beads will unbalance the trackball. review of the Periboard 328 mechanical keyboard