Black Box ServSwitch Jr. SW621A-R2 Manual page 22

Because the ServSwitch Jr. currently only supports "stream mode" (continuous)
mouse data but the IBM ThinkPad has to handle mouse data in "prompt mode"
(burst-on-request), don't try to attach any ThinkPad computers to the Switch,
either directly or through docking stations.
Use only the generic Microsoft mouse driver MOUSE.COM, version 4.0 at least and
preferably version 9.01 or higher. If you're running Windows
be loaded in Windows as well as in DOS. Do not, on any of your switched CPUs,
run any programs or TSRs, or enter any DOS commands, that change the settings
of the mouse port after the driver has been loaded.
Although the ServSwitch Jr. resists minor transient surges that can be caused by
rapidly cycling power, certain keyboards are sensitive to such transients. Because
your shared keyboard's power comes through the Switch, wait at least three
seconds after powering down the Switch before powering it up again, or the
keyboard might not reset correctly.
The ServSwitch Jr. is designed to support 101-, 102-, 104-, or 105-key keyboards
and keyboard-scan modes 1, 2, and 3; it's also designed to work with PC-type
CPUs/keyboards that use 5-pin DIN or 6-pin mini-DIN keyboard connectors. The
Switch might not work properly with keyboards that have proprietary keys or
connectors or use proprietary keyboard-scan modes.
CHAPTER 4: Operation
® 3.x, this driver must
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