PROPHET-600

Document No: MIDI-4
Issued: January, 1983
Revised:

Copyright 1983 by
SEQUENTIAL CIRCUITS, INC.
All rights reserved.

Note: This page applies to the first revision of the Prophet-600, later revisions have added features.

PROPHET-600 MIDI IMPLEMENTATION
Dave Smith, SCI

Unless otherwise specified, status/data bytes are given in binary, while numbers in descriptions are decimal.

TRANSMITTED DATA

First Byte Second Third Description
1000 0000 0kkk kkkk 40H Note off (key # = 36(C0) - 96(C5).)
1001 0000 0kkk kkkk 40H Note on (key # = 36(C0) - 96(C5).)
1100 0000 0ppp pppp --- Prog change from front panel (00-99),
if enabled.
1111 0000 01H (SCI ID) 02H, 0ppp ppp, data (32)..., F7 (EOB) Prog data dump (sent upon request)
(32 nibbles, 16bytes)
Note: Data in program data dumps is sent in four-bit nibbles, right justified, least significant nibble sent first.
1110 0000 0 p6 p5 p4 p3 p2 p1 p0 (LS 7 bits)
0 p13 p12 p11 p10 p9 p8 p7 (MS 7 bits)
Pitch wheel change (when enabled).
Note: 14-bit signed 2's complement pitch wheel value. 8-bit accuracy
(Bit p0=0, bits p9-p13 are sign bits). If both bytes=0, no pitch change (wheel centered).
1011 0000 1 000m mmmm Mod wheel amount data (if enabled).
Note: Wheel values are only sent whenever a change in position is detected.

RECOGNIZED RECEIVE DATA

First Byte Second Third Description
1000 xxxx 0kkk kkkk 0vvv vvvv Note off. Velocity ignored.
1001 xxxx 0kkk kkkk 0vvv vvvv Note on (if vel=0, turn note off.
Otherwise velocity ignored.)
Note: When the note-on code is sent once (1001 xxxx), new notes can be played
without using a new note on or off status byte, by using velocity=0 for note off.
1100 xxxx 0ppp pppp --- Prog change (If enabled, simulates
prog# change from front panel.)
1111 xxxx 01H (SCI ID), 00H, 0ppp ppp, F7 (EOB) Prog dump request (ignores if ID is wrong)
1111 xxxx 01H (SCI ID), 02H, 0ppp ppp, data (32)..., F7 (EOB) Prog data dump (ignores if ID is wrong)
(32 nibbles, 16 bytes)
1110 xxxx 0 p6 p5 p4 p3 p2 p1 p0 (LS 7 bits)
0 p13 p12 p11 p10 p9 p8 p7 (MS 7 bits)
Pitch wheel change (when enabled).
Note: The 14 bits are shifted, after receipt, as follows:
p13 p13 p12 p11 p10 p9 p8 p7 p6 p5 p4 p3 p2 p1 p0 0
That is, p13 is assumed to be the sign bit and hence is moved into the MSB. The LS byte is shifted to put the bits
in the correct order. For reference, bit p6 = 1 semitone in the Prophet-600. Also note that this pitch value does not
go through auto-tune, and as such should not range beyond +/- a perfect 5th, for optimum tuning.
1011 xxxx 1 000m mmmm External modulation amount (if enabled).
Note: This amount is added to MOD wheel and INITIAL MOD AMOUNT pots
to establish total amount of modulation.

MODE

The Prophet-600 is always in Omni mode.

FRONT PANEL CODED FUNCTIONS

When the RECORD switch is held down, pressing a PROGRAM SELECT switch will activate the following functions :

Switch Function
1 Enable/Disable program change, both transmit and receive (toggles).
On power up, MIDI program change is disabled.
2 Dump current program. Sends the 16 bytes of the stored Non-
Volatile program that is displayed in the PROGRAM display,
regardless of mode (Preset, Manual, Edit, etc.)
3 Reserved for machine service function (pitch wheel deadband
centering).
4 Enable/Disable Pitch and Mod wheel control transmit and receive.
Disabled on power up.
Note that if two -600's are connected together, to work correctly, both switch function 1 and 4 must be done on both instruments.

PROPHET-600 PROGRAM BIT MAP

16 bytes of program data

Byte <-- MS BIT ---- LS BIT -->
0 B0 A6 A5 A4 A3 A2 A1 A0
1 D0 C3 C2 C1 C0 B3 B2 B1
2 E1 E0 D6 D5 D4 D3 D2 D1
3 F4 F3 F2 F1 F0 E4 E3 E2
4 H0 G5 G4 G3 G2 G1 G0 F5
5 I1 I0 H6 H5 H4 H3 H2 H1
6 J3 J2 J1 J0 I5 I4 I3 I2
7 K4 K3 K2 K1 K0 J6 J5 J4
8 M2 M1 M0 L3 L2 L1 L0 K5
9 O2 O1 O0 N3 N2 N1 N0 M3
A Q2 Q1 Q0 P3 P2 P1 P0 O3
B S2 S1 S0 R3 R2 R1 R0 Q3
C U2 U1 U0 T3 T2 T1 T0 S3
D V6 V5 V4 V3 V2 V1 V0 U3
E Z7 Z6 Z5 Z4 Z3 Z2 Z1 Z0
F ZF ZE ZD ZC ZB ZA Z9 Z8
POT BITS
A = OSC A PULSE WIDTH (7)
B = PMOD FIL ENV AMT (4)
C = LFO FREQ (4)
D = PMOD OSC B AMT (7)
E = LFO AMT (5)
F = OSC B FREQ (6)
G = OSC A FREQ (6)
H = OSC B FINE (7)
I = MIXER (6)
J = FILTER CUTOFF (7)
K = RESONANCE (6)
L = FIL ENV AMT (4)
M = FIL REL (4)
N = FIL SUS (4)
O = FIL DEC (4)
P = FIL ATK (4)
Q = AMP REL (4)
R = AMP SUS (4)
S = AMP DEC (4)
T = AMP ATK (4)
U = GLIDE (4)
V = OSC B PULSE WIDTH (7)
SWITCH BITS
Z0 = OSC A PULSE
Z1 = OSC B PULSE
Z2 = FIL KBD FULL
Z3 = FIL KBD 1/2
Z4 = LFO SHAPE (1=TRI)
Z5 = LFO FREQ AB
Z6 = LFO PW AB
Z7 = LFO FIL
Z8 = OSC A SAW
Z9 = OSC A TRI
ZA = OSC A SYNC
ZB = OSC B SAW
ZC = OSC B TRI
ZD = PMOD FREQ A
ZE = PMOD FIL
ZF = UNISON