NonStop System Glossary

dial-out point
A system console from which incident reports are sent to a service provider. Incident reports are
sent only from system consoles defined as the primary and backup dial-out points (the primary and
backup system consoles).
DID
See destination ServerNet ID (DID).
DIMM
See dual inline memory module (DIMM).
direct connect
Connection from the Fibre Channel ServerNet adapter (FCSA) to the Enterprise Storage System
(ESS) without going through an FC switch.
direct current (DC)
Electric current that flows in only one direction. Contrast with alternating current (AC).
direct jump area
One of sixteen 256-megabyte portions of the 4-gigabyte virtual address space. A RISC jump
instruction has the ability to jump directly to any location within its own direct jump area without
having to use a far jump table.
direct memory access (DMA)
A technique for transferring data from main memory to a device without passing it through the
CPU.
directory
A type of Open System Services (OSS) special file that contains directory entries, which associate
names with files. No two directory entries in the same directory have the same name.
directory entry
In the Open System Services (OSS) file system, an object that associates a filename with a file.
Several directory entries can associate names with the same file. See also link.
directory loop
In the Open System Services (OSS) file system, an error condition in which a directory is identified
as its own parent directory.
directory special file
See directory.
directory stream
In the Open System Services (OSS) file system, an object with an opaque data type. A process
can sequentially read directory entries from a directory stream.
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