26
SERVSWITCH™ JR. MP
4.3.5 S
END
N
ULL
B
YTE
(PC CPU
S WITH
PS/2 M
OUSE
P
ORTS
O
NLY
)
PS/2 type mice send control data to CPUs in three-byte increments. Sometimes,
because of electronic transients, unusual power-up effects, or plugging and
unplugging of cables from live equipment, the currently selected PC type CPU in a
ServSwitch Jr. MP 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 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”). To issue the Send Null Byte command, press
and release the left Control Key, then type [N].
If the mouse still isn’t right after you issue this command, the CPU must have
been two bytes out of sync. Issuing the command again should do the trick.
The CPU will be thrown out of sync if it has a PS/2 mouse port and it’s in sync
when you issue this command. Issue this command two more times to get it back in
sync again. This command has no effect on Mac CPUs or on CPUs that are
attached to the Switch through an RS-232 mouse port.
If you have version 9.01 or higher of the Microsoft mouse driver, the CPU should
never get out of sync. Contact Microsoft if you would like to upgrade your
Microsoft mouse driver.
4.3.6 I
DENTIFY
ROM
Unfortunately, as with all complex equipment, problems might arise with your
ServSwitch Jr. MP that require the assistance of technical-support personnel. One
of the things technicians might want to know when they attempt to diagnose and
correct your problem is the revision level of your Switch’s ROM. This command
causes the ServSwitch Jr. MP to send the three-character “
x.x
” ROM level to the
currently selected CPU as ASCII keyboard data; these characters will be echoed
back to the shared monitor if you are at some type of prompt. (You
must
be at
some kind of prompt or screen capable of displaying typed-in keyboard characters,
or you will not see the Switch’s response.) To issue the Identify ROM command,
press and release the left Control key, then type [I].
4.3.7 K
EEP
S
ETTINGS
The Keep Settings command saves the current state of the ServSwitch Jr. MP’s
keyboard-selectable settings to nonvolatile memory (NVRAM), where they become
the new default (loaded at power-up) settings. To enter the command from your
keyboard, press and release the left Control Key, then type [K]. The six keyboard-
selectable settings are described in the next six sections.
