VMS Help Sys Parameters, MULTITHREAD  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    MULTITHREAD controls the availability of kernel threads
    functions. Specify one of the following values:

    Value       Description

    0           Both Thread Manager upcalls and the creation of
                multiple kernel threads are disabled.

    1           Thread Manager upcalls are enabled; the creation of
                multiple kernel threads is disabled.

    2-256       Both Thread Manager upcalls and the creation of
    (Alpha      multiple kernel threads are enabled. The number
    only)       specified represents the maximum number of kernel
                threads that can be created for a single process.

    The maximum value for MULTITHREAD is 256.

    MULTITHREAD is an AUTOGEN parameter.