TM 5-6675-316-14
f. Flashing a particular character.
(1) When the keyboard is operated, the output data is automatically stored in
a buffer memory by the keyboard interface logic. The microprocessor processes the
functional data, and the font character information is read from the disc, which is
then stored in the display memory. The display memory supplies this data to the
character generator logic which processes it for presentation on the CRT.
(2) When an end-of-the-line decision is detected, the program transfers data
from the lower half of the screen to the top. At the same time, it begins to
process data sequentially from the display memory, passing instructions to the
various phototypesetter functions which will set the characters on the film. As the
film is advanced, it is stored in a take-up cassette mounted on top of the console.
When the required copy has been set, the film is advanced into the take-up cassette
and then cut off. The take-up cassette can then be removed and taken to the pro-
cessing machine.
2-3.2 Detailed.
a.
Photo unit.
(1) The photo unit is basically a camera which exposes images from a motor
driven disc through a lens system and onto photographic material. The disc contains
four rows of characters, width information and timing information. The light source
flashes when triggered by the timing information and illuminates only the required
character. The image of this character then passes through an enlarging lens, a
collimating lens, collecting lens, 45-degree angled mirror and onto the-photographic
material. By moving the collecting lens assembly backward and forward, lines of
type can be formed. The photographic material is moved at the end of each line in
preparation for the next.
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