User manual

VSMP Reference
43
XQDRIVER’s default of 5 seconds to the value specified by VSMP option XQTIMEOUT (default
is 255). If this patch is not applied, and simulator thread operating DEQNA is preempted for
more than few seconds, OpenVMS will falsely detect timeout on the controller and shut it
down. It is not advisable to operate DEQNA or DELQA without this patch enabled. However if
VAX MP is operated in strictly uniprocessor mode, with just primary CPU active, and ASYNCIO
on XQ devices is disabled too, then this patch makes no difference. This patch is
automatically disabled if VSMP LOAD detects that XQDRIVER is not loaded and there are no
XQ devices configured.
XQTX1 – XQTX10,
XQRX1 – XQRX4
These patches are required for proper memory synchronization when using DEQNA or DELQA
Ethernet controller. They must be enabled when DEQNA or DELQA is in use and XQDRIVER is
loaded. Without these patches Ethernet controller cannot be operated when running system
in multiprocessor mode (with more than one CPU in active set) and will produce data
corruption and other controller failures. These patches are automatically disabled if VSMP
LOAD detects that XQDRIVER is not loaded and there are no XQ devices configured.