! Set up VD: units with ADVD, assuming VDDRIVER is already
! loaded somewhere.
DEFINE VERB ADVD
   IMAGE VD$DST:ASNVD.EXE
     parameter p1,prompt="VDn:",value(required,type=$device),label=UNIT
     parameter p2,label=FNAM,prompt="file",value(type=$infile)
     qualifier ASSIGN
     qualifier DEASSIGN
; Uses ASNVD image. Note that vddriverv3a.mar contains code to
; handle the assign function in the FORMAT code. For now we don't
; use this, but just let the priv'd image do it.
; Needs CMKRNL at least. Maybe some others.