Glossary - IBM 3279 2A Maintenance Information

TOP MAR. top margin
TP. test point
trig. trigger
V. volts
vert. vertical
'fide video
VTL. vendor transistor logic
Glossary
bezel. The front panel that surrounds the display
screen.
coaxial cable. A cable consisting of one conductor,
usually a small copper tube or wire, within and
insulated from another conductor of larger diameter,
usually copper tuhing or copper braid.
converged, convergence. Ideally, the condition in
which the red. blue. and green electron beams
together produce a white display with no colored
fringes.
degauss coil. A coil that prevents misconvergence
due to stray magnetic fields.
feature bus. The logical data path in the 3279,
along which the base machine communicates with
added features.
jitter. An irregular random repetitive movement of
an image on the screen.
miscoDvergeDce. Opposite in meaning to
"convergence
II
(see above),
3279 MIM
W A. write address
W /0. without
WR. write
)LF. microfarads
p.S.
microseconds
pel. Picture element.
mODochrome. Single color.
phosphors. The coatings on the inner surface of the
screen that emit light when hit by an electron
beam.
pincushion (distortion). The appearance of the
display when the sides of the raster are curved.
raster. The pattern of lines on the display screen
that is traced out by the scanning electron beams.
The raster may
be
visible when the brightness
control is turned up or when intensity override is
engaged.
retimed. With improved timing.
ripple. An ac signal on a dc level.
Abbreviations and Glossary G-3