Basic HTML Version
DEDICATED SWITCHES
r-------,
:CPU :
: BOARD:
I
I
I
I
I
I
I
I
I
I
I
J205
r-------------------,
:
COIN DOOR :
:
INTERFACE :
:
BOARD
:
I
Jl
J3
I
Orange -Brown (U17-5)
Dl
'
,
H-----=-----'------H,
4
----f--o
I
D2
7
3
4
U17-11) D3
D5
6
5
4
2
D4
6
7
B
D6
3
2
D7
9
Orange-Gray
(U
16-5)
DB
I
I
I
,
,
L
-'
Block
I
I
I
I
---------------~
Coin Acceptor Switches
01 - Left Coin Chute
02 - Center Coin Chute
03 - Right Coin Chute
04 - Fourth Coin Chute
Control Switches
05 - Normal Function, Service Credits; Test Function, Escape
06 - Normal Function, Volume Down; Test Function, Down
07 - Normal Function, Volume Up; Test Function, Up
08 - Normal Function, Begin Test; Test Function, Enter
DEDICATED SWITCH CIRCUIT
CPU BOARD
+12V
OPEN
L OFF
CLOSED
H ON
---------,
COIN DOOR
I
INTERFACE :
Coin Acceptor
BOAR D
:
~~ntrol
Switch
I
I
+5V
1
Dedicated Input
The dedicated switches operate similar in the matrix, except that instead of a column circuit there is a direct tie to
ground. Therefore, the column side is constantly active (low).
When a switch closes, the row side (dedicated input) of the circuit activates. The "+" input to the LM339 drops below
+5V, therefore the output is low. Since the row circuit (dedicated input) is tied directly to ground through the switch,
the switch is considered closed by the microprocessor.
When the switch opens, the "+" input to the LM339 is above
+5V, it output is high and the row is inactive
3-3