REV.-A
When
the
operational amplifier is activated,
the
SPI, RDSP, and slave
CPU
output
signals are fed
to
the
non-inverted
input
terminal (pin 3)
of
the amplifier
through
the
respective resistors and
the
capacitor C18, are amplified and
the
output
is obtained
at
pin 5.
The inverted
input
terminal (pin 2) is grounded.
When
the
voltage
at
the
negative pole terminal
of
C18
deviates
from
the
ground level, therefore,
the
voltage divided
by
the
variable resistor
VR1
is
supplied
to
the
non-inverted
input
terminal (pin 3) and amplified.
C18 is inserted
to
reject
the
DC
component
of
the
incoming
signals.
2.13.2
System
Outputs
to
Speaker
Anyone
of
the
sounds listed in Table
2-23
can be
output
to
the
speaker(s)
from
the
system via
the
BASIC SOUND command, e.g.,
/n
the
application program.
Table
2-23
System
Outputs
to
Speakser
Occasion
Sound
Power on in Restart mode One
short
sound
of
selected frequency
Power on in Continue mode
One long sound
of
selected frequency
Before password
entry
One "pee roe"
Alarm/wake
while
power
off
Three "peeroes
"
Alarm/wake
display Three
"
peeroe
"
The buzzer is sounded
by
a
combination
of
the
above sounds.
Example:
When
the
computer
enters
the
Restart
mode
at
the
Wake
time
while
power
is off.
Three "peeroes" and one
short
sound
ofthe
selected frequency occur.
2-112
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