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When the 'data available' signal and the data character
are accepted by the system, power to the restore magnets
is dropped. The keyboard restoring bail moves to the
front of the keyboard (under spring tension) carrying the
latched interposer with iL An elongated interposer pivot
hole allows the interposer to move to the front, clearing
the latch spring (Figure 1-4). The interposer return spring
forces the interposer up off of the bail and behind the latch
spring. The interposer pushes the latch spring to the rear,
allowing the EDS to open.
As the interposer moves to the rear, the interposer
projection strikes the <lobber, and pivots it from its rest
position. When the keylever is released, it pivots upward
and the <lobber return spring restores the <lobber to its
normal position above the interposer.
As the bail moves to the front, it moves under all the
unoperated interposers (Figure 1-2) and prevents them
from operating. While the keyboard restore bail travels
toward its forward stop, the bail contacts (which are EDS
switches) close, providing the 'bail contact' or 'restore'
signal to the system, or keyboard logic. This indicates the
bail has traveled its full restoring stroke and the restore
magnets can again be energized. The keyboard remains .
locked and the 'bail contact' or 'restore' signal remains
until the restore bail magnets are picked and sealed.
The 'bail contact' or 'restore' signal drops the 'data
available' signal and holds it reset. These electronic inter-
locks allow the time for the EDS switch to open. Thus,
there is only one output from the keyboard for each latch
key pressed.
Figure 1-4. Latch Key (Restoring)
The keyboard is locked by the ball interlock (Figures
1-3 and 1-5) while the interposer is latched down. An
operated interposer goes between the interlocking balls
and takes up the· clearance between the balls. Other inter-
posers can not be operated until the first one is restored
because the balls can not separate to allow another inter-
poser to enter. The keyboard is locked by the restore
bail during restore time. Therefore, the next key cycle
can begin only when the restore magnets are again picked
and sealed.
lnte,pom•
n
c:Qo
Ball
Interlocks
Figure 1-5. Ball Interlocks
Interposer Return Spring
Elastic Diaphragm Enc Kybds and 5475 Data Entry Kybd
(3/71)
1-3.
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