The SWI, SWI2, and SWI3 vectors point to routines that read the corresponding pseudo vector from the process’ descriptor and dispatch to it. This is why the <code>[[F$SSWI]]</code> system call is local to a process; it only changes a pseudo vector in the process descriptor.

The SWI, SWI2, and SWI3 vectors point to routines that read the corresponding pseudo vector from the process’ descriptor and dispatch to it. This is why the <code>[[F$SSWI]]</code> system call is local to a process; it only changes a pseudo vector in the process descriptor.