JVC AX-M9000 Service Manual page 17

TC74HC27AF-W(IC531) : Noa gate
1. Pin layout
1A 1
1B
2
2A 3
4
2B
5
2C
6
2Y
GND
7
(TOP VIEW)
TC74VHC08F-X(IC281) : Dataline buffer
1. Terminal layout
1A 1
1B 2
3
1Y
2A 4
2B 5
6
2Y
GND
7
(TOP VIEW)
14 Vcc
13 1C
1Y
12
3C
11
10 3B
3A
9
3Y
8
14 Vcc
13 4B
4A
12
4Y
11
10 3B
3A
9
3Y
8
2. Truth table
C
A B
Y
X
H X L
L
X X
H
X H L
X
L L
L H
X : Don't Care
2. Truth table
A B Y
L
L
L
L L
H
L L
H
H
H H
X : Don't Care
AX-M9000
1-17