ServSwitch User's Manual

CHAPTER 6: Keyboard Commands

use the mouse but don’t disable the mouse either, take these precautions:

• If you never actually use the mouse with the CPU (as would probably be the

case if, for example, the CPU were a Novell

NetWare

file server), either don’t

plug the mouse strand of the CPU Cable into the CPU’s mouse port, or don’t

load a mouse driver at all. If you do use the mouse, are running Windows 3.x,

and sometimes exit to DOS, make sure you load a DOS mouse driver before

running Windows.

• If you’ve loaded a DOS mouse driver and are going to use an application such

as NetWare that disables the PS/2 mouse, first REM out any statements in your

startup files (AUTOEXEC.BAT, etc.) that load the mouse driver, then reboot

the computer to remove the mouse driver from memory. (Having the mouse

driver unload itself doesn’t do the job.)

6.12 Reset/Enable Mouse in Windows NT and UNIX: [Ctrl] O

This is the best command for recovering a non-working mouse if the selected CPU

is running Windows NT or any variant of UNIX. When you press and release left

[Ctrl], then press and release the letter [O] key, the Matrix ServSwitch sends “reset

codes” to the PS/2 mouse port of the currently selected CPU. This will cause the

CPU to reinitialize its Windows NT or UNIX mouse driver, which will reset or re-

enable the mouse.

If the selected CPU has gotten into a state in which it doesn’t recognize the

“wheel” on a Microsoft IntelliMouse or other supported wheel-type PS/2 mouse,

you can also use this command to force the CPU’s mouse driver from non-wheel to

wheel mode.

6.13 Send Null Byte to PS/2 Type Mouse: [Ctrl] N

PS/2 type mice send control data to CPUs in three- or four-byte increments.

Sometimes, because of electronic transients, unusual power-up effects, or plugging

and unplugging of cables from live equipment, the currently selected CPU in a

Matrix ServSwitch system can lose one or two bytes of this control information and

get “out of sync” with the shared mouse. In this situation, the mouse might seem to

refuse to move the pointer or cursor, open windows for no reason, or exhibit other

strange behavior. To get the CPU back in sync, send this command (press and

release left [Ctrl], then press and release the letter [N] key) to tell the Switch to

send a “null byte” to the CPU’s PS/2 mouse port. This has no other effect than

getting the CPU “caught up.”

If the mouse still isn’t right after you issue this command, the CPU must have

been two or three bytes out of sync. Issuing the command up to two more times

should do the trick.