Coin Slot Magazine - #V8N7 - 1983 - March [International Arcade Museum]
foes, the green class contains three
members:
Figure 4B
Slick,
a
small
character wearing glasses;
impish
Sam,
Slick's counterpart sans glasses;
A
and a small green ball. Unlike the
first two classes, contact with the
three green characters is desirable.
Touching the ball freezes all objects
except Q*Bert, allowing the player
to hop around the screen unmolested
Contact with Sam or Slick earns
Figure 5
points for the player. An added in
11.3V
Ea 7.2V
v:
OV.
centive for catching these two quickly
is that they change the color of any
cube touched by Q*Bert to its previous
color.
The player has one defense besides
Figures 4A and 4B. We have a
center tapped stepdown transfor-
_.
fi
Figure o
mer with an applied primary voltage
of 80 VAC and a turns ratio of 5:1. I
:
former is therefore 16 VAC. How-v^
-
The secondary voltage of this trans- u*\
ever, since we have grounded the
center tap of the transformer's sec
ondary, the applied voltage to each
diode is 8VAC (Erms). During the
first half cycle of the applied AC volt
age (time 1) point A of the secondary
swings positive, forward biasing the
:
the green ball; discs that hover near
the edge of the pyramid. Hopping
onto a disc transports Q*Bert to the
pyramid's top. A well timed jump will
cause Coily to plummet off the
pyramid, scoring additional points
for the player. A disc is not reusable,
so a player must carefully plan the
use of discs.
Scoring for the game is simple.
The operation of this circuit is the
Making contact with Slick or Sam
following: during the first half cycle
of the secondary voltage waveform
jump off the pyramid scores 500
scores 300 points, causing Coily to
top diode. At the same time, point B
swings negative, cutting off the bot
(when point A is positive and B is
points, and changing a cube's color
tom diode. Therefore, only a positive
voltage is felt at the load, point C. At
time 2 point A of the secondary
swings negative, turning off the top
diode, but point B is now going
negative) current flows from point B
to the target color scores 25 points.
through diode 3 to ground through
Players are also awarded bonus
the load through diode 1 to point A.
points for successfully completing
Notice that with point A positive
and B negative (180 degrees out of
phase) both diodes 1 and 3 are
a round. The bonus starts at 1,000
positive allowing a positive voltage
to again be felt at point C when the
bottom diode turns on. The resultant
waveform is shown in Figure 5. It
turned on while diodes 2 and 4 are
cut off. During the next half cycle
current flows from point A through
has a ripple frequency of twice the
input AC voltage (normally 60 Hertz).
The output ripple frequency is usu
ally 120 Hertz. Using the previous
equation for Ep, we find we have a
peak voltage of 11.3 volts DC. Since
our ripple frequency has doubled, a
new equation is used to find:
Ea : Ea = Ep x 0.64
Therefore, for this circuit Ea is 7.2
volts DC.
Even though a full wave rectifier
circuit has advantages over a half
wave rectifier, there are two major
problems with this circuit. It requires
a center tapped transformer, which
is often more expensive than a nor
mal transformer. And it produces a
peak output voltage that is only half
the value of a half wave rectifier. A
circuit that combines the best fea
tures of half wave and full wave rec
tifier circuits is the bridge rectifier
(Figure 6).
MARCH 1983
The play itself offers players the
chance to develop patterns while
diode 4 to ground through the load
new chal-
lengea The second level makes
(in the same direction!!!) through
diode 2 to point B. The net result of
to reach the target color. Another
this circuit is a positive DC waveform
at point C having the same appear
ance as Figure 5 (twice the ripple
frequency of a half wave rectifier)
but, if we were to use the same
transformer as in Figure 4A leaving
the center tap open (ungrounded),
Ep and Ea would be doubled.
Next article: filtration and regu
lation.
ARCADE
PARADE
m
o
Continued
m.c from page 11
:
u
m
e
s The second class of foes consists
ro
ed f ade-mu of a series of red bouncing balls.
d
a
nlo
These balls tumble down the
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pyramid, smashing everything in
:
their path. Contact with these objects
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© The International Arcade Museum
points and increases by 250 points
for each round thereafter.
results in the loss of one life.
The third class consists of the
green characters. As with the purple
constantly presenting
players jump onto each cube twice
level has cubes revert back to their
original color the second time they
are touched. Coupled with a pat
terned release of objects, players
can feel they are mastering the
game without doing so too quickly.
Graphically the game is appealing.
Q*Bert is a cute character that is
well animated. The purple foes are
sinister looking, and the green class
appears mischievious The animation
is basic but well executed. Players
can enjoy the movement and actions
of the game's characters. The
ambience created by the cartoon
speech bubbles is a treat This simple
touch creates a special link between
player and game; the game expresses
the feelings that the player has
when he loses a life.
Continued on page 18
13
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