execute channel program

from The Free On-line Dictionary of Computing (8 July 2008)

Execute Channel Program
EXCP

   <operating system> (EXCP) An {IBM} system for low-level file
   access, where the programmer is completely responsible for
   providing a list of device-specific "channel comands" to be
   executed by {I/O channels}, {control units} and/or {devices}.
   The {operating system} will simply check the "{CCW}" chains
   for security purposes (access invalid memory or outside of
   {file extents}) and then schedule them for execution.

   (2005-08-08)