Cpu Program; Test Mode - Roland sh-101 Service Manual

NOV.1st,1982
CPU PROGRAM
The CPU
80C49-6-7301
controls the various
modes
and
functions
of the
SH-101 through
a series of
programmed
steps, as
shown
in
the attached flowchart. These
actions
are described below.
Note:
Steps 3 through
1
3 are
a series of
program
steps that
are sequentially
executed by
the
CPU
at
1.5 to
3.5msec
intervals.
The
CPU
can modify
this se-
quence any
time
new
data
is
input.
1.
TEST
MODE
The
Test
mode
allows easy adjustment
of the
SH-101.
To
enter the Test
mode,
first
turn the
power
switch Off.
This
is
necessary as the Test
mode
cannot
be entered
while the
SH-101
is
in
any
of the
normal operating
modes.
Now
simultaneously press both the
LOAD
and
KEY TRANSPOSE
buttons and
turn the
power
switch
On.
The
CPU
sets the voltage
at
the
KCV
and
at
the
Range
to zero
and
turns the
Gate
Off.
The
unit
is
now
in
the Test
Mode. The
voltage values
at
the
KCV
and the Range, and the status
of
the
Gate change
ih
each
of the function
modes
listed
below.
Function Button
KCV
Range
Gate
PLAY
2.75V
OV
Off
ARPEGGIO
DOWN
2.5V
OV
Off
ARPEGGIO
U&D
4.75V
OV
On
ARPEGGIO
UP OV
4.75V
On
LOAD
OV
OV
Off
To
enter a
normal
mode,
either press the
Hold button
down,
or
turn the
power
switch Off
and
then back
On
again.
2.
INITIAL
SET
The
CPU
performs
Initial
Set
when
the
power
switch
is
turned
On
or
when
the
HOLD
button
is
pressed during
the Test
mode.
This operation deletes
all
the data that
is
stored
in
the
built-in
RAM,
such
as
Keyboard and
switch
mode
data,
but
does
not delete the
Sequencer
data.
3.
RANGE DATA READ
The
CPU
reads
and memorizes
the positions
of
the
VCO
Range,
TRANSPOSE
(L,
M
and
H)
and
GATE/TRIG
{LEO
)
switches.
4.
RANGE DATA OUTPUT
The
CPU
sends
the
VCO
Range
data (read
in
Step
3)
to
the
D/A
Converter where
it
is
converted
into
analog-
equivalent values.
RangeSelector Range Data
16'
8
'
4'
T
IV
2V
3V
4V
If
the
CPU
contains
Key Transpose
data (stored during
step
8
of
the previous program execution), the
Key
Shift
data
is
added
to
the
Range
Selector data.
For example,
if
the user selects the
lowest F-key and
sets
the
Range
Selector
to
16', the
Range
data value
will
be
0.417V.
Likewise,
if
the
user selects
a
higher
C-key and sets the
Range
Selector
to
2', the
Range
data value
will
be 5V.