Atari Breakout - Coin Recognition; Q Latch and Antenna; Start Recognition; Free Game Selector

I
,...,,
3.4.6
COIN
RECOGNITION
(SHEET
3,
ZONES
D
5
THROUGH
7):
In
each
coin
mechanism
a
coin
switch
·is
activated
each
time
a
coin
passes
through
the
mechanism
and
on
into
the
cash
box.
The
inverter
latches
"debounce"
the
signals
produced
at
the
switch
contacts;
the
CSW1
and
CSW2 signals
cause
the
coin
counter,
an
electromechanical
counter
in-
side
the
coin
mechanism
assembly,
to
advance
by
one
count
each
time
a
coin
is
deposited
into
the
game.
The
flip-flop
stages
F8
and
F9
produce
the
COIN#1
and
COIN#2
signals
that
set
the
Q
latch
when
a
coin
is
deposited.
The
remaining
portion
of
the
circuit
discriminates
between
one
or
two
credits
per
coin,
as
determined
by
the
position
set
on
Switch
S3.
The
COIN
signal
produced
at
L9
pin
6 is
connected
to
the
credit
accumulator;
each
pulse
causes
the
accumulator
to
add
one
count.
Flip-flop
H8
will
test
the
COIN#1
and
COIN#2
signals
for
a
valid
width.
3.4.7
Q
LATCH
AND
ANTENNA
(SHEET 3, D
4):
Transistors
Q1
and
Q3
form
a
discrete
component
latch.
Note
that
they
are
complementary-Q1
is
PNP
and
Q3
is N
PN.
The
two
stable
states
of
this
latch
are:
(a)
Latch reset,
with
neither
transistor
conduct-
ing
(meaning
that
the
game
is in
the
attract
mode)
(b) Latch set,
with
both
transistors
conducting
(meaning
that
the
game
is
in
the
play
mode).
This latch
is
made
to
power
on
in its reset state.
The
first
coin
deposited
into
the
game
after
initial
appli-
cation
of
power
will
set
the
latch,
enabling
credit
and
the
start
of
the
play
sequence.
This
latch
is
nor-
mally
reset
after
the
player
misses a
volley
on
the
last
ball
served,
provided
that
no
credits
are
remaining
in
the
credit
accumulator
at
that
time.
However
the
latch can also be reset
if
transistor
Q2
goes
into
con-
duction.
This
should
be
the
case
only
if
a static spark
occurs
near
the
game and
is
received
by
the
antenna
that
connects
to
the
base
of
Q2.
3.4.8
START
RECOGNITION
(SHEET
3,
ZONES
CS
THROUGH
8):
The
start
push
button
switches
con-
nect
to
flip-flop
EB,
but
the
flip-flop
cannot
recog-
nize
a player's
depressing
a
button
unless
the
game
is
in
the
attract
mode.
Also,
depression
of
the
"Two
Player
Start"
is
not
recognized
unless
at
least
two
credits
are
remaining
in
the
credit
accumulator.
Latch
F7
remembers
which
start
push
button
had
been
depressed.
The
attract
flip-flop
E6
will
remain
in
the
"set"
condition
until
it
is
reset
at
the
end
of
the
game
sequence
(the
signal
EGL
and
the
signal
Q).
3.4.9
FREE
GAME
SELECTOR
(SHEET
3,
ZONES
A
&
B 5
THROUGH
8):
This
circuit
compares
the
most
significant
bits
in
each
player's
score
register
with
the
settings
selected
on
switch
S1.
The
J8
latches are
each set
if
the
player
attains
the
bonus
score
level,
but
this
can
only
happen
once
per
play
sequence.
Also a
pulse
is
produced
by
the
BONUS
COIN
signal
after
each
latch
is
set.
Each
pulse
wi
11
cause
the
credit
accumulator
to
advance
by
one
count.
The
BONUS
COIN
signal also
triggers
Multivibrator
N8,
so
that
the
FREE
GAME
TONE
signal
will
cause
the
speaker
to
produce
the
buzzing
sound.
3.4.10 CREDIT ACCUMULATOR
AND
START
LAMP
DRIVERS
(SHEET 3,
ZONES
A
&
B 2
THROUGH
5):
The
binary
up/down
counter
L8
serves
as
the
credit
accumulator.
The
tie-back
connection
between
pins
12
and
11
prevents
the
counter
from
advancing
past a
count
of
15.
The
counter's
outputs
are
decoded
to
produce
the
2
CREDIT
and
1
OR
2
CREDIT
signals
which
are
used
to
turn
on
the
gates
of
the
silicon
controlled
rectifiers
Q4
and
QS,
and
elsewhere
in
the
circuitry.
When
conducting,
each
SCR
provides
the
filament
current
for
the
lamps
behind
a
start
switch.
The
credit
accumulator
is
decremented
by
the
1 CR START
and
2 CR START
signals
produced
when
a
player
depresses a
lighted
start
push
button.
3.4.11
BRICK DISPLAY
(SHEET
1,
ZONE
D 7):
The
memory
capacity
of
the
RAM
device
in
location
L3
is
divided
in
half
so
that
the
brick
pattern
for
each
player
is
stored
independently.
At
the
very
start
of
a
play
sequence
a
full
brick
pattern
is
restored
for
each
player
by
the
SET
BRICKS
signal.
As
play
pro-
gresses,
the
time
coincidence
of
the
BRICK
HIT
sig-
nal
with
the
4H
through
16H
and
16V
through
128V
timing
signals
will
determine
which
bricks
are
elimi-
nated
from
each
player's
brick
pattern.
The
output
signal
from
this
circuit,
BRICK DISPLAY,
is
combined
in
the
playfield
generation
circuit
with
the
other
sig-
nals
for
the
stationary
objects
in
the
TV
picture.
3.4.12
PLAYFIELD
GENERATOR
AND
VIDEO
SUMMING
(SHEET 1,
ZONES
C
5
AND
D 3
AND
4):
The
sidewall
and
backwall
boundaries
are
derived
from
the
timing
signals
produced
in
the
sync
countdown
chain,
and
are
then
combined
with
the
BRICK
DISPLAY
signal
to
produce
the
PLAYFIELD
signal at Gate H4
pin
3.
The
composite
video
signal
to
the
TV
monitor
is
produced
at
the
summing
point
formed
by
the
junction
of
resistors
R41,
R42, R43,
R51,
R52
and
CR6.
The
horizontal
and
vertical
TV
synchronization
information
is
coupled
through
CR6,
the
ball
through
R43,
and
the
paddle
through
R41.
3.4.13
POINTS
COUNTER
(SHEET 2,
ZONE
C
5):
Counter
N9
is
forced
to
parallel-load
information
when
the
BRICK
HIT
signal
triggers
multivibrator
N8.
The
counter
then
counts
down
to
zero
at a rate set
by
the
SCLOCK
signal.
The
pulses
produced
at
N7
pin
11
are
used
to
drive
the
brick
sound
generator
circuit,
so
that
a
distinct
audible
"tick"
sound
will
be
produced
for
each
point
value
of
the
brick
right
after
it
has
been
hit
by
the
ball.
After
gating
in
N7,
the
COUNT
2
signal
is
produced
that
drives
the
score
register
for
player
2, and
also
the
COUNT
1 signal
for
player
1's score register.