TM 5-6675-316-14
2-3. TECHNICAL PRINCIPLES OF OPERATION.
2-3.1 General. The composing machine is a keyboard operated phototypesetter.
It consists of a keyboard with CRT display and console containing the photo unit.
From one type disc, 74 point sizes are available in four type faces. These are all
accessible from the keyboard. Format information such as type font, size, line
length, line remainder and leading are all clearly indicated on the CRT.
The selected characters are instantly visible on the CRT display upon keystroking.
These can easily be changed or corrected as desired, before printing. When a line
is completed, it is automatically set by the photo unit while the next line is being
keyboarded.
The microprocessor, housed in the mainframe, performs the following functions:
Handling all input control and alphanumeric keystrokes whenever they occur.
a.
b.
Loading the character generator memory, to be capable of displaying the
keystrokes on the CRT.
Reading a stored character width code from the character disc.
c.
d. Calculating functions related to point size and line length.
Commanding the various stepping motors to the proper positions.
e.
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