The DYN_ routines are a set of routines for obtaining chunks of virtual memory dynamically. They are intended as a more tidy alternative to the DAT_TEMP - DAT_MAP method. For small amounts of memory they make calls to the relevant VMS system services to obtain virtual memory, whereas for larger amounts they create temporary mapped files on SYS$SCRATCH. No debris is left when the memory is released. The routines reside in ASTLIB.