Casio CE-2400 Service Manual

— 13 —
RF
REG
X
Z
6-4. Mode key switch status read
The CPU knows the mode switch status by voltage level of pin No.1.
The voltage level is down by resistor. Each voltage is as shown below.
16 Kohms
6.2 Kohms
2 Kohms
560 ohms
Mode REG X Z RF OFF
Voltage (V) 196 3.29 4.36 0.98 0
▲
To Pin No.1 of CPU
6-5. RAM address/head drive signal switching circuit
The CPU uses the port for RAM address (A0 ~ A11) and head drive signal (HD1 ~ HD6).
To select the RAM address and head drive signal, CPU use "STEP MOTOR COM" signal.
When CPU wants to read the RAM chips, CPU stops "STEP MOTOR COM" signal.
The CPU controls RAM address (A0 ~ A12) using IC 10 because CPU has 7 ports.
First, CPU sends RAM address (A4 ~ A7, A10, A11) to IC10 and IC10 store the address data.
Next, CPU sends RAM address (A0 ~ A3, A8, A9, A12, A14) to RAM.
At the same time, CPU sends clock signal to IC10.
Then, IC10 outputs stored data (A4 ~ A7, A10, A11). In this way, CPU controls RAM address.
P140
P141
P142
P143
RESET
X2
X1
IC(VSS)
XT2
XT1
VSS
P00/INT4
P01/SCK0
P02/SO0/SB0
P03/SI0/SB1
P10/INT0
P11/INT1
P12/INT2
P13/TIO
P20/PTO0
P21
P22/PCL
P23/BUZ
P30

AN0
AVREF
VDD
VDD
P113
P112
P111
P110
P103
P102
P101
P100
P93
P92
P91
P90
SI1/P83
SO1/P82
SCK1/PB1
PPO/P80 dall
KR7/P73
KR6/P72
KR5/P71
KR4/P70
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
AN1 AN2 AN3
P150/AN4 P151/AN5 P152/AN6 P153/AN7
AVSS
P120 P121 P122 P123 P130 P131 P132 P133
80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65
25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
KR3/P63 KR2/P62 KR1/P61 KR0/P60 P53 P52 P51 P50 VSS P43 P42 P41 P40 P33 P32 P31
M4
M3
M2
M1
Ki7
Ki6
Ki5
Ki4

SG1
SF1
SE1
Ki0
Ki1
Ki2
Ki3
RP
PWD
Ki8
Ki9
DW
STEP MOTOR COM
MOTOR
BUZZER
SD1 SC1
SB1 SA1
SDP0
SG0
SF0
SE0

SD0 SC0
SB0 SA0
Dg4 Dg3 Dg2
PAD1 PAD2
MOTOR ERROR

R ON/OFF  A14 Kc00 Kc01 Kc02 D0 D1 D2 D3
R-COM
J-COM
CE
WE
RESET
A
B
C
G2A
G2B
G1
Y7
GND
Vcc
Y0
Y1
Y2
Y3
Y4
Y5
Y6
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
28 27 26 25H5A8A10 24H6A9A11 23 22 21 20 19 18 17 16 15
1 2 3 4 5 6 7 8 9
10 11 12 13 14
Vcc
WE
A13
A8 A9
A11
OE
A10
CE
I/O8 I/O7 I/O6 I/O5 I/O4
A14 A12 A7 A6 A5 A4 A3 A2 A1 A0 I/O1 I/O2 I/O3 GND
9
5
6
7
8
4
3
2
1 2 3 4 5 6 7 8

16 15 14 13 12 11 10 9
Vcc
Q6
D6 D5
Q5
D4
Q4
CLOCK
CLEAR Q1 D1 D2 Q2 D3 Q3 GND
H6A9A11
H5A8A10
H4A3A7
H3A2A6
H2A1A5
H1A0A4
STPCLK
FEEDA12
VCC
GND
VDD
56K
R79
C44
IC13 TC74HC138AP
234567
RA 3MS5636F
1
Vcc
VDD
VDD
C28
C103
1
GND
DWS
GND
56K R70
C471 C33
PAD2
PAD1
MODECOM
VCC
VDD
GND
C30 C31
D29
1S2473
TFC104
C103
GND
VDD
VLED
1
2
3
DA1
GND
H4A3A7 H3A2A6 H2A1A5 H1A0A4
FEEDA12
GND
VDD
VCC
H2A1A5 H4A3A7  H6A9A11  STPCLK
H1A0A4 H3A2A6

H5A8A10
C29
TFC103
TFC104
C41
IC8 BA12003
IC9 BA12003
16 1
10 7
IC11 LC36256AL
TC74HC174
IC10
VP
D27 1SR-35-100A
2SD1853
R72
100K
1
2
3
GND
R54
C32
C101
GND
1M
C25
SB007W035
C102
R69 8.2K
R71 56K
R67 CRH100-J-6R8
10K
D28
1S2473
GND
R43
2K
RP

6 5 3 2 4
1
VCC
MS5635F
RA2
10K

R68

Q18
GND
GND
Dg1 
C102 
C17 
GND
C-002RX
IC5 µPD75517GF-400-389
53253-0310
RA5 MS1038F
CN4

Casio CE-2400 Specifications

General

Brand	Casio
Model	CE-2400
Category	Cash Register
Language	English