Canon A-1 Repair Manual page 133

8. CNTL (8P)
i 2y
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'II
n.'
-,
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........ 1···
... .
. .
. .
.. .
.
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.
-
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.
:2V
:-
.. .
... .
... .
Fig. 3-26
. ...
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.
2.!!-3V
0.4--0.6)1
9. AVO (9P)
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.
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.
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2V
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r---
2.!!-3.0V
0.4-0.6V
Fig. 3-27
(Trigger: 07)
Self timer Time 1, Time 2,
Lens Manual setting and
Stopped-down diaphragm
singles enter the CPU thru
this pin.
Fig. 3-26 Gray Code:
LSD 00001010
CNTL code uses T.B 3 thru
T.B 6 so : 0101
From the CNTL Table, we
decode this as full aperture
metering, manual and the
self timer set to 2 seconds.
The T.B 7 code "0" also
indicates shutter speed
priority.
(Trigger: 07)
This is the code for the
maximum aperture of the
lens mounted on the camera .
(If
no
lens 1s mounted,
the code 1s the code for
f/5.6.). This code actual-
ly serves the dual purpose
of
AVO,
maximum aperture
information input, and
AVe,
maximum aperture correction.
(The AVC signal actually
originates within the IC.)
Fig. 3-27 Gray Code:
00001100
AVO uses T.B 3 thru T.B 6
0110 which is f/l.4 as shown
in the AVO, AVC table.
67