If
no
program
change
is
desired, you
can either
transmit
the last
program
number,
or
the
code
FF(H)
which the
Prophet simply
ignores. Except
for the
FF code,
the
Prophet
will
sense
an
error
if either of the
two
MSBs of the
program byte
are set.
NOTE;
Be
sure
the
Prophet
is switched to
PRESET mode when
you want
to
change
programs.
Also,
when
switching Scale
programs, the Prophet must
first
be
manually
placed
into
Scale
mode.
(Status
B can be
used for changing the
program only . Status E
can be
used
for
receiving
"short"
keyboard data. See below.)
6-^
STATUS 2: TRANSPOSE ON
This
status byte is used to enable the sequencer
transpose function. Once
the
Prophet
receives code 04(H), you can transpose the
entire playback sequence
over
a four-
octave
range by
just hitting
a
key between
CO
and C^ on
the
Prophet.
The
transposition is equal to the
interval
between C2
and the key played. For
example,
to
transpose
down a
fifth,
hit
Fl. To transpose
up a
major seventh from
the original
key,
hit
B2. To
transpose back to the original
key,
hit C2.
The Prophet keyboard
will not function normally
until
it receives a STATUS
5,
CLEAR
TRANSPOSE.
6-7
STATUS 3: SAVE TO TAPE
This status
byte is used
to extract
the contents of
the current
Non-Volatile
Program
RAM
file
from
the
Prophet,
without using
the
independent
CASSETTE
interface.
Since
a
file is organized
as
'fO
24-byte programs,
the file
uses 960 of
its 1024
(IK)
assigned bytes. The least-significant seven bits
of each
byte
represent
a
programmable
potentiometer setting
of
0-127
steps, while the MSB represents
a
switch
setting (l=on,
O=off). The Prophet has another area of RAM
called "Scratchpad" in which
the current
status of the machine is registered. When selecting
a
program
in
PRESET
mode,
a set
of 24 bytes is transferred from
NV
RAM to
the Scratchpad, with
the
"pot" bits
filling
the pot table and the
switch
bits being regrouped into
the switch status table. Here is
how
the pot and switch bits are grouped in each NV program:
Switch
Bit
(7)
Pot Bits (0-6)
Byte
OSC
A PULSE FILT ATK
Byte 1 OSC A SAW
FILT DEC
Byte
2
OSC A SYNC FILT SUS
Byte
3
OSC B SAW FILT
REL
Byte 4
OSC B TRI AMP
ATK
Byte
5 OSC B
PULSE
AMP
DEC
Byte
6
OSC B KBD AMP
SUS
Byte 7
UNISON AMP
REL
Byte
8
POLY-MOD
FREQ A FILTER
CUTOFF
Byte 9
POLY-MOD
PW A FILT ENV AMT
Byte 10
POLY-MOD
FILT MIX OSC B
Byte
1
1
LFO
SAW OSC B PW
Byte
12
LFO
TRI
MIX OSC A
Byte 13
LFO
SQUARE
OSC A
PW
CMIOOOD
2/82
6-5
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