Icom IC-3200A Service Manual page 13

2.
Matrix
Switch
The
matrix data from the
LOGIC B UNIT
are fed to B1, B2,
and
B4
on
the
CPU
through SI
to activate the
scan speed,
the
scan
timer,
and
the
memory
lock functions.
3.
Busy
Matrix
for
the
Speech Synthesizer
When
the
speech synthesizer
is
activated,
it
sends a busy
signal to
D3,
and
turns
ON
D1
B2 on
the
main
matrix
by
means
of
01
.
This
alerts
the
CPU
that
the synthesizer
is
activated.
The
CPU
waits
until
the
busy signal
is
LOW
before
continuing.
4.
BEEP
Circuit
The
BEEP
circuit
is
a
phase
oscillator
consisting of
IC3D,
R5,
R6, R7, C9,
Cl
0,
and Cl
1
which
feeds out a signal to
01
3
on
the
MAIN UNIT when
the control gate
is
HIGH.
5.
DIAL Clock
Circuit
This
circuit
consists of IC2, IC3, 02,
R9, RIO, R11,
C6
and
C7,
which form
the rotary
encoder.
When
turning the
encoder
dial,
one
shot pulses are
generated from IC2A.
Meanwhile,
02
generates a
HIGH
or
LOW
signal to
the
U/D
port
on
the
CPU
for
UP
or
DOWN
tuning. Also,
IC2A sends
sensor signals to the
CK
port
on
the
CPU.
3
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6