JVC KB-700 Service Manual page 6

KB-700 B/N/H
J
ROM (MSM83055-18RS)
ROM memorizes all the program and also receives switching informations.
Reset
Control
input
Data bus
CE
T
^
J
40
vcc
CE 2 39
P B7
C LK 3
38 P B6
RES 4
37 P B 5
NC 5
36 P B4
READY 6
35 P B3
10/M 7
34 P B 2
For
8 33
P B
1
rd 9 32 PB0
fow
1 0 3
1
P A7
ALE
1 1 30 P A6
A D0
1
2 29 P A 5
A D 1 1 3
28 P A4
A D 2
1
4 27 P A 3
A D 3 1 5
26 P A2
A D 4
1
6
25 P A 1
A D 5 1 7
24 PA0
A D 6
1
8 23 A DIO
A D 7
1 9 22 A D 9
GND
20 2 1 A D 8
Outputs of scanning signal
of switching on/off information
]
Control input
(from CPU port 2)
Fig. 5
■ RAM (MSM81C55RS)
RAM memorizes codes by CPU's control.
IC1 outputs the sound source of the solo
presets, rhythm pulse, key pulse and
signals for switching solo presets.
IC2 turns out signals for POTS data,
switching of orchestra presets, turning on
LEDs, etc.
IC2
UKP
Orchestra glide
1 MHz input
for Solo
Solo 2' OUT
Control input
(from CPU)
Data bus
P C 3 1
V/
40
+ 5 V
P C 4 2 39
P C 2
T 1 N 3 38 PC 1
RES 4 37 P C 0
P C 5
5 36 P B 7
TOUT 6 35 P B 6
1 O/M 7
34 P B 5
CE
8
33 P B 4
RD 9
32 P B 3
WR 1 0 3 1
P B 2
ALE 1 1 30 PB 1
D B 0 1 2 29 PB0
DB 1 1 3 28 P A7
D B 2 1 4 27 PA 6
D B 3 1 5 26 P A 5
D B 4 1 6 25 P A4
DB 5
1 7 24 PA 3
D B 6 1 8
23 PA 2
D B 7 1 9
22 PA 1
D B 8 20 2 1
P A 0
Rhythm ON
u
Backing,
Envelope OUT
Solo synthe.
preset select
Auto-rhythm
pulse OUT
Fig. 6
Tremolo control
LKP output
Reset,
Sustain control
Control input
Data bus
P C 3
1 40 + 5 V
P C 4 2
39 PC 2
—|
T 1 N 3
38 PC 1
RES 4 37 PC0
PC 5 5 36
P B 7
TOUT 6 35 P B 6
1 O/M
7 34 P B 5
CE
8
33 P B 4
RD 9 32 P B 3
WR
1 0
3 1 P B 2
ALE 1 1
30 P B 1
DB0
1 2 29 PB0 —
DB 1 1 3
28 P A 7 —
DB2
1 4 27 PA 6
D B 3 1 5
26 P A 5
D B 4 1 6
25 PA 4 —
D B 5 1 7
24 PA 3 —
D B 6 1 8
23 PA 2
D B 7 1 9
22 PA 1
D B 8 20
2 1 PA0
-
LED lighting
control
Orchestra
preset control
output
Data output
for POTS
Fig. 7
6