MPE/iX Glossary of Terms and Acronyms (32650-90887)

26 Chapter1
Glossary of Terms
LONER, SCRATCH, and UNKNOWN.
disk swapping The process of moving data segments from memory to disk and from disk
to memory; and for moving code segments from disk to memory.
diskette See flexible disk.
dismounted A disk not recognized by the system.
distributed database A database whose data is located on a number of different
computers, which may be in different geographic locations.
distributed systems Systems in which some or all of the processing functions are in
different places and connected by transmission facilities.
distributed system line (DS line) The communications line between two computers,
controlled by the distributed system network.
distributed system network (DSN) A system of hardware and software data
communications products spanning multiple Hewlett-Packard product
lines.
dot matrix printer A printer in which each character is represented by a pattern of dots.
download The process of transferring a block of information from one computer
system to another.
driver 1. In hardware, driver refers to a circuit that is capable of supplying
specific current and voltage requirements.
2. In software, driver refers to a program that is capable of controlling a
specific input/output device. See control program.
DRT number Device reference table number. The physical I/O address of a device
controller, displayed in the second column of the I/O configuration table
listed during the SYSDUMP dialog. An MPE V/E index into the DRT.
dumb terminal A terminal which can only display and transmit data.
DUMP 1. The MPE/XL ISL DUMP utility writes system main memory and
secondary storage to tape. DUMP also, optionally, attempts a software
reboot from disk.
2. See cold dump.
Dump Analysis (DPAN) See dump analysis tool (DAT)
Dump Analysis Tool (DAT) An MPE/iX program. It produces a formatted listing of the
contents of main memory after a system failure or shutdown. This aids in
the analysis of fatal system events such as process hangs, system failures,
or hardware failures. This tool is similar to the MPE V dump analysis
program (DPAN).
duplex The method of transmission that allows simultaneous two-way
communication. Duplex is usually called full-duplex. The opposite of
half-duplex.
duplicative 1. To echo input operations to a corresponding display without
intervention by the operating system software.