IBM 6400 Setup Manual page 293

NAK Negative acknowledge. Not acknowledged.
N/A Not available or not applicable.
NL New Line (3287 only).
NLQ Abbreviation for near letter quality font. This is the
highest resolution mode supported on the 6400.
Not Ready Mode Offline. The printer is not ready to receive and process
commands and data.
nS Nanosecond
NVFU Direct Access Vertical Format Unit. See also DAVFU.
NVRAM Abbreviation for non-volatile random access memory.
The storage is permanent, in the sense that information
is not lost when the printer is powered off.
OCR Abbreviation for Optical Character Recognition. A
process by which a machine can "read" characters
printed in a special standardized font. Data are read by a
photoelectric optical scanner and can be recorded on
magnetic tape or disk. OCR-A and OCR-B are two widely
used OCR fonts.
Ohm A unit of measurement for electrical resistance.
PA Program Attention. Used in application programs.
parity (check) Parity checking is the addition of non-data bits to data,
resulting in the number of bits that are set to a "1" being
either always even or always odd. Parity is used to detect
data errors.
PC Personal Computer
PCBA Printed Circuit Board Assembly
pel The smallest element of a physcial medium that can be
independently assigned color and intensity. Pels per inch
is often used as a measurement of presentation
granularity. Synonymous with picture element, pixel.
PI Abbreviation for Paper Instruction. A physical hardware I/
O line used in conjunction with the eight data bit lines.
When PI is set high, it indicates that the eight data bits
are interpreted as a paper motion command instead of
printable data.
pica A name indicating a monospaced font with a pitch of 10
cpi (and usually 12 points in height). Pica is also used in
typography as a unit of measurement equal to 1/6 inch.
pitch The number of text characters printed per horizontal inch.
Specified in characters per inch or cpi.
pixel Derived from picture (PIX) ELement. The smallest
displayable picture element on a video monitor or
printable unit. In printing, a pixel is a dot.
293