StorageTek L700 Service Manual page 347

modulator/demodulator (modem) An
electronic device that converts computer
digital data to analog data for transmission
over a telecommunications line (telephone
line). At the receiving end, the modem
performs the reverse function.
MPC card (1) The central processing unit
card for the tape library. (2) The main logic
card in the library.
MPCL card Replaces the MPC card in new
machines manufactured after 9/02. The MPCL
card function is identical to the MPC except
that it can be jumpered to operate on a native
LVD/SE interface; there is no need to install
the MPV and MPW cards for LVD operation.
MPF card The DC power supply card for
the tape library.
MPK card An EEPROM-based module that
holds upgraded library feature data. See also
personality module.
MPU card The Fibre expansion card for the
tape library.
MPV card Acts as the backplane on the
CPCI assembly for either the fibre (MPU)
interface card (both MPC and MPCL cards) or
the LVD (MPW) interface card (MPC only).
MPW card The LVD/SE card (attached to the
MPV card) that enables LVD/SE operation for
an MPC card only.
Multiple Virtual Storage (MVS) IBM's
Multiple Virtual Storage, consisting of MVS/
System Product Version 1 and the MVS/370
Data Facility Product operating on a System/
370 processor. (IBM)
N
negative acknowledgement (NACK) Used
by the recipient of a communication to tell
95846
the sender that the data was not accurately
received.
network gateway A four-byte notation that
makes the library accessible to a large
network, which consists of two or more
subnets, through a gateway connection.
network file system (NFS) A distributed
file system and its associated network
protocol.
non-backward read compatibility
(NBRC) The inability of an SDLT 220N tape
drive to read recorded data from an earlier
version of DLT tape drive. Contrast with
"BRC" (above).
non-maskable interrupt (NMI) An
interrupt which cannot be shut off by
executing a disable interrupt instruction on
the microprocessor. These interrupts are
principally reserved for fatal conditions (for
example, parity errors, watchdog timer
faults).
non-volatile random access memory
(NVRAM) A section of memory that will
retain its information even when power is
removed from the equipment.
O
offline Not available for functional use by
the host CPU.
online State of being controlled directly by
or in direct communication with a computer.
Available for functional use.
open fiber control (OFC) Open Fiber
Control (OFC) cables incorporate a safety
mechanism that prevents damage to the
human eye when the connection (link) is
disconnected.
oz An abbreviation for ounce. A unit of
weight equal to 28.35 grams.
Fourteenth Edition
StorageTek Proprietary
Glossary
Glossary-7