Atari Breakout - Player Score Registers; Empty Wall Detector; Serve Wait; Ball Serves Counter

10
3.4.14
PLAYER SCORE REGISTERS (SHEET 2,
ZONES D 6
THROUGH
8): The BCD
counters
N6,
M6
and
L6
form
a score
register
for
player
2, and H6,
J6
and
K6
form
one
for
player
1.
Both
registers are reset
to
all zeros at
the
beginning
of
each play sequence.
Pulses
of
the
COUNT
1 signal
increment
the
player
1
register and
those
of
the
COUNT
2 signal
increment
the
player
2 register.
3.4.15
EMPTY
WALL DETECTOR
(SHEET
2,
ZONES
D
4
&
5): The signals
K1,
G1
and
D1
are
produced
in
the
player
1 score register, and
the
signals~,
G
2
and
D2
are
produced
in
the
player
2 score register.
After
a
player
has
knocked
away
all
the
bricks
flip-flop
F4
is
set
as
soon
as
the
ball
hits
either
the
paddle
or
the
backwall
boundary.
This can
happen
only
once
per
play
sequence;
the
flip-flop
is reset
only
at
the
be-
ginning
of
a
play
sequence.
For
player
1
the
FPD1
signal
will
cause
the
RAM
in
location
L3
to
restore a
full
set
of
bricks
for
player
1
only.
The
FPD.z
signal
will
do
this
for
player
2.
3.4.16
SERVE
WAIT
(SHEET
1,
ZONES A 1
THROUGH
3):
After
the
ball disappears
off
the
end
of
the
screen
flip-flop
A3
is
set via
A3
pin
10,
and
the
SERVE
WAIT
signal goes
high.
Also
the
LED
inside
the
serve
push
button
·
lights
up.
Now,
no
new
ball
can
appear
on
the
screen
until
a
player
depresses
the
serve
button,
thus
forcing
the
SERVE
signal
to
low.
The
circuit
is disabled
during
the
attract
mode.
3.4.17 BALL
SERVES
COUNTER
(SHEET
1,
ZONES
B,
C 1
&
2):
During
a
two-player
game a pulse is
produced
at gate D2
pin
B,
PLAY
CP,
after
the
SERVE
WAIT
signal
(applied
at
pin
3
of
flip-flop
AS)
goes
high.
During
a
one-player
game
two
pulses
in
quick
succession are
produced.
These
PLAY
CP
pulses
increment
binary
counter
B4,
the
ball
serves
counter.
The state
of
the
counter's
pin
14
least signif-
icant
bit
output,
the
signal
PLAYER
2, tells
which
player is
up.
When
pin
14
is
low
it
means
that
player
·
1
is
up,
and
when
it
is
high
player
2
is
up.
The
counter's
other
three
outputs,
BALL#
A,
BALL#
B,
and
BALL#
C, are
decoded
to
produce
the
EGL (End
of
Game
Level)
signal.
The
position
selected
on
Switch
S4
will
determine
whether
EGL
goes
high
after
3 ball serves
or
after
S.
3.4.18
BALL
MOTION
COUNTERS
(SHEET
1,
ZONES
B
&
C 6, 7, 8):
Counters
C7 and
CB
form
an
X-direction
ball
motion
counter,
and
B7
and
B8
form
a
Y-direction
ball
motion
counter.
The X
direction
is
defined
as
along
the
long
dimension
of
the
picture,
and
the
Y
direction
as
along
the
short
dimension.
Both
counters
are
driven
by
the
CLOCK
signal,
but
they
operate
independently
from
the
counters
in
the
sync
countdown
chain.
On
the
motion
counters
the
number
of
clock
pulses
required
to
reach
terminal
count
is
dependent
upon
what
parallel
data
has
been
preset
into
the
counters.
The parallel data
for
counter
C7 is
the
signals
CXO,
CX1
and
X2;
for
counter
B7
they
are
Yo,
Y1
and
Y2.
These signals are
produced
in
the
ball
motion
controls
circuit.
The
counters
reach
terminal
count
once
per
picture
•
frame. The ball
motion
is
accomplished
by
changing
the
time
when
the
counters
begin
counting.
The ball
speed is
accomplished
by
changing
the
number
of
equivalent
counts
in
the
preset parallel data.
The
signals
BRICK
SOUND,
VB
HIT
SOUND
and P
HIT
SOUND
are
tapped
off
the
counters
as
convenient
waveforms
for
use
in
producing
the
tick,
bounce
and
blip
sounds.
Outputs
from
the
ball
motion
counters
are
decoded
to
produce
the
BALL signal.
3.4.19
BALL
HIT
AND
MOTION
CONTROLS
(SHEET
1, ZONES
A,
B,
C 3
THROUGH
7): Data is
clocked
into
flip-flop
E6
to
produce
a
BRICK
HIT
sig-
nal each
time
the
ball hits a
brick.
The
BP
HIT
signal
~roduced
when
the
ball
hits
the
paddle;
the
EITB
RlT
is
produced
when
the
ball
hits
the
backwall
boundary;
and
the
VB
HIT
is
produced
when
the
ball
hits
either
sidewall
boundary.
Latch
F7
is
set
when
the
ball hits a
brick,
but
is
not
reset
until
the
ball
hits
either
the
paddle
or
the
backwall
boundary.
This
action
of
the
latch insures
that
only
one
brick
hit
is
recognized
at a
time.
The
state
of
flip-flop
DS
(pins
Sand
6)
deter-
mines
whether
the
ball
will
move
toward
the
backwall
or
toward
the
paddle
end
of
the
screen.
The
states
of
flip-flops
A6
pin
Band
A6
pin
6
affect
the
angle
of
rebound
when
the
ball strikes an
object.
Counter
BS
is
the
volleys
counter.
Its
outputs
are
decoded
so
that
ball
motion
will
be
speeded
up
after
4
successive
volleys
during
any
one
serve,
and
speeded
up
still
more
after
12
successive volleys.
Flip-flop
DS
pin
9
detects
when
either
a
S-point
or
a
7-point
brick
has been
hit
during
any
one
volley.
The
flip-flop's
output
signal
SU
causes
counter
BS
to
parallel-load
all
1's,
and
the
ball
speed
will
then
be
immediately
increased
to
its fastest value.
3.4.20 BRICK
HIT
SOUND
GENERATOR
(SHEET
2,
ZONES
C
&
D 1
THROUGH
3): The rate at
which
the
SCLOCK
signal
increments
the
game's
points
counter
N9 (subparagraph 3.4.13)
is
much
too
high
for
use
in
producing
audible
tick
sounds
directly.
For
this
reason
the
COUNT
signal
is
applied
to
a
brick
sound
generator
circuit
in
order
to
produce
a
slower
rate signal.
Up/down
counter
F6
is
preset
to
all 1 's at
the
start
of
a play sequence. The
brick
hit
point
count
pulses
of
the
COUNT
signal
increment
the
counter
F6
at a
very
high
rate and also set latch
F7.
The signal
produced
at
J9
pin
12,
by
gating
the
latch
output
with
V SYNC
and
multivibrator
A7's
output,
then
decre-
ments
counter
F6
back
down
at a
very
slow
rate. This
same signal also
triggers
multivibrator
AB
at
pin
11.
With
this
arrangement
multivibrator
AB
pro-
duces
an
output
each
fime
counter
F6
is
dee-
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