Casio QT-2100 Service Manual

— 64 —
10. HD74LVC138 (IC21)
11. HD74LVC244 (IC3,5)
11
12
13
14
V
CC
1
2
3
4
5
6
7
10
A
GND
8
9
15
16
A
B
C
Y
7
G
1
G
2B
G
2A
Y
0
Y
1
Y
2
Y
3
Y
4
Y
5
B
C
G
2A
G
2B
G
1
Y
7
Y
6
Y
5
Y
4
Y
3
Y
2
Y
1
Y
0
Y
6
G 2B
H
X
X
L
L
L
L
L
L
L
L
C
X
X
X
L
L
L
L
H
H
H
H
B
X
X
X
L
L
H
H
L
L
H
H
A
X
X
X
L
H
L
H
L
H
L
H
Y
0
H
H
H
L
H
H
H
H
H
H
H
Y
1
H
H
H
H
L
H
H
H
H
H
H
Y
2
H
H
H
H
H
L
H
H
H
H
H
Y
3
H
H
H
H
H
H
L
H
H
H
H
Y
4
H
H
H
H
H
H
H
L
H
H
H
Y
5
H
H
H
H
H
H
H
H
L
H
H
Y
6
H
H
H
H
H
H
H
H
H
L
H
Y
7
H
H
H
H
H
H
H
H
H
H
L
G
1
X
X
L
H
H
H
H
H
H
H
H
G
2A
X
H
X
L
L
L
L
L
L
L
L
Inputs
Outputs
Enable Select
H: High
L: Low
X: Don t care
11
12
13
14
15
16
17
18
19
20
V
CC
2G
1Y1
2A4
1Y2
2A3
1Y3
2A2
1Y4
2A1
1
2
3
4
5
6
7
8
9
10
1G
1A1
2Y4
1A2
2Y3
1A3
2Y2
1A4
2Y1
GND
1 T/R
A0
A1
A2
A3
A4
A5
A6
A7
GND
Vcc
OE
B0
B1
B2
B3
B4
B5
B6
B7
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
Inputs
OE T / R
LL
LH
HX
Output Y
Bus B Data to Bus A
Bus A Data to Bus B
Z
H : High
L : Low
X:
Don t care
Z: High impedance
12. HD74LVC245 (IC2,6)
28 Vcc
27
WE
26 A13
25 A8
24 A9
23 A11
22
OE
21 A10
20
CE
19 I/O8
18 I/O7
17 I/O6
16 I/O5
15 I/O4
A14 1
A12 2
A7 3
A6 4
A5 5
A4 6
A3 7
A2 8
A1 9
A0 10
I/O1 11
I/O2 12
I/O3 13
GND 14
Vcc
GND
CE
WE
OE
A0 ~ A14
I/O1 ~ I/O8
ADDRESS
BUFFER
DECODER
DATA
CONTOROL
CIRCUIT
CONTOROL
CIRCUIT
MEMORY
ARRAY
LOGIC
OUTPUT
BUFFER
INPUT
BUFFER
13. LC35256FT (IC1)

Casio QT-2100 Specifications

General

Brand	Casio
Model	QT-2100
Category	Cash Register
Language	English