Black Box ACU3001A, ACU3009A, ACU3022A manual Correcting the PS/2 Mouse if IT Gets OUT of Sync

SERVSWITCH™ BRAND CAT5 KVM MICRO EXTENDER

Note that the Extender will automatically reinitialize the keyboard and mouse whenever you attach them. If a reset doesn’t help your remote keyboard or mouse, try cycling power to the Remote Unit.

7.3.2CORRECTING THE PS/2 MOUSE IF IT GETS OUT OF SYNC

On rare occasions, you might notice that, instead of behaving normally, your mouse pointer is moving and jumping erratically all over the screen (and possibly selecting things at random). This is usually a sign that the PS/2 mouse has gotten “out of sync” with the Micro Extender or that the Micro Extender has gotten out of sync with the CPU’s PS/2 mouse port.

Explanation: PS/2 mice send mouse data in 3- or 4-byte packets. As long as the CPU knows which bytes mark the start and end of each packet—which it virtually always does as long as the mouse is directly connected to it—it can correctly interpret the mouse signals. But when mice are disconnected and reconnected, or when mouse signals pass through other devices on their way to the CPU, it is sometimes possible for the CPU or the intervening devices to lose track of where the mouse-data packets begin and end, with the result that the cursor/pointer begins behaving bizarrely.

If this happens in some mouse extender/switch systems, the only solution is to either kill and reload the mouse driver or reboot the PC. But the Micro Extender has a feature you can use to painlessly recover from this kind of glitch. First try to reset the mouse by pressing and releasing Scroll Lock on the keyboard as described in Section 7.3.1. If this doesn’t work, send the “Null Mouse Command” in order to resynchronize the CPU’s mouse port. To do this with the ACU3022A, press and release the hotkey, then press and release the left-arrow (number 4) key on the keyboard’s numeric keypad (not the number 4 on the top row of the keyboard). With either of the other models, take these steps:

1.Press and hold down both the left and right mouse buttons.

2.Press and release the [Scroll Lock] key on the associated keyboard, then release the mouse buttons.

3.Check mouse operation.

4.If the mouse isn’t yet operating correctly, repeat steps 1 through 3 as many as two more times. (If this still doesn’t help, call Black Box Technical Support.)

When the Micro Extender receives the Null Mouse Command, it sends a “null byte” of mouse data to the CPU; this has no effect other than to get the CPU “caught up” with the mouse. You might have to issue the command as many as

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