Page 93 - Attack From Mars

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DEDICATED SWITCHES
r------------------,
:
COIN DOOR
:
INTERFACE
:
BOARD
I
J1
J5
1--------,
:CPU :
: BOARD:
I
J205 :
~
I ~
[
~
tJ
~
I
I
L
_j
Coin Acceptor Switches
D1 - Left Coin Chute
D2 - Center Coin Chute
D3 - Right Coin Chute
D4 - Fourth Coin Chute
: Oronge-Brown (U17-5)
D1
:I;l
--:l
,
I
I
: Oronge- Red (U17-7)
I
D2
I
7
5
I
I
I
I
I
: Oron_ge-Block (U17-11) D3
I
I
I
6
6
I
Oronge-Yellow (U17-9)
D4
I
5
I
I
I
I
Oronqe-Green (U16-9)
D5
I
4
7
I
I
I
I
Oronge- Blue (U16-11) D6
I
S
I
.3
: : Orange-Violet
(U16-7)
D7
I
,
2
9
I
I
i
!
: Oronge-Gray (U16-5)
DS
I
W
I
1
: Block
I
Ground
I
10
I
1,----
L
_j
Control Switches
D5 - Normal Function, Service Credits; Test Function, Escape
D6 - Normal Function, Volume Down; Test Function, Down
D7 - Normal Function, Volume Up; Test Function, Up
D8 - Normal Function, Begin Test; Test Function, Enter
OPEN
OFF
CLOSED
H ON
,-- - - - - -- - - - -- -l
I
COIN DOOR
I
I
:
INTER~ACE :
Coin
Acceptor
.1205 II
I
aOAR:\
:
or
vi'
0
~
Control Switch
I
I
I
I
X
;
o~-
; Orange-XXXI
I
I
:
tl
I Block
I,
r-------1
01--;.--------+1'1 5r----------j
3
f--+----___J
1
I
tl
~--------------------------------------~
L
_
DEDICATED SWITCH CIRCUIT
r------
-------------------------------~
SWITCH
CPU BOARD
+5V
o
i
+i2V
I
74LS240 L-11-;;0-L
K
---LM-33-9-'~,
CD ..
I
-
qN414S
----
---~
B
+ -
1-47-0Pf
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