Star Tech Journal

Issue: 1982-December - Vol 4 Issue 10

6
STAR*TECH JOURNAL/DECEMBER 1982
DON'T SIT
ON YOUR
"Asteroids"!
Convert to new hot full
color games with
XC-1 00 Asteroids
Cabinet Conversion Kit.
All you need is PCB.
XC-1 00 KIT
*$495.*
This is a super kit. It is
well engineered and
can be installed in less
than 2 hours. Your
total satisfaction is
guaranteed.
*
*
Kit Includes
19" Color Monitor
* Isolation Transformer
*
*
*
*
* *
*
Heavy Steel Monitor
Mounting Bracket
(allows both vertical
and horizontal
picture tube
mountings)
Picture Tube Bezel
Tinted Plastic Safety
Screen
Choice of Control
Panels with Joystick
and Buttons
Monitor Bracket
Template for Easy
Mounting
All Required Hardware
Clear Plastic Top
Attractlon Panel
Easy Instructions
*
WVGO, Inc.
Send Check or Order UPS COD to
15000 Main Street
Gardena, CA 90248
213-516-9525
ROWE BC-35 BILL CHANGER* WILLIAMS' GAMES
By Todd Erickson, Summit Amusement, St. Paul, MN
Rowe BC-35 Bill Changer
Rowe has just introduced their new
BC-35 bill changer, They have made a
lot of excellent changes in this bill
changer. The first one is security. This
is a new cabinet for the first time in
years. It is higher for the optional large
capacity hoppers. The cabinet has been
made stronger, thus increasing security.
The transport now has a belt to help
remove pieces of paper. The handle on
the hoppers help prevent losing coins if
a changer is dumped. Older models had
an optional maximum capacity board.
This option is now available with a
switch. This changer has another
important first for Rowe - it will
separate one dollar bills from five
dollar bills. It does this using two
stackers. I feel this will be a big time-
saver in large arcades. There are only
two minor things that have not been
done. The first is the most important:
the return button sticks in. This flaw
has been in their machines for many
years. When the button is in, it will not
accept money. My machine was a
sample and Rowe told me that this
problem would be eliminated during the
production run. The cover for the test
vend must be closed while the machine
is in use. If it isn't, the switches can be
depressed with a wire. They should
have a self-closing cover. Again, I
expect to see the change made shortly.
With the kind of job Rowe has done
with this machine, it is evident that
they are after 100% of the market. I
recommend buying their blue and white
model for arcades.
Williams' Games
Many people felt that "Defender'' was
luck for Williams. Releasing
"Stargate", "Robotron", "Moon
Patrol" and now "Joust" is not luck. It
proves that they have gone from a
pinball company to one of the
paramount video companies of the
'80s.
Williams' games are made very
well. As with all games, they have a
few minor flaws. The most major is the
2-way joystick that wears out from a
lot of use. This is an inexpensive
assembly that can be purchased from
Williams or Wico. A light grease on
the pivot will help reduce wear.
Williams also introduced translucent
lexan buttons. This material is far
superior to any others for buttons. It is
a bullet-proof plastic. I recommend
these for replacement on all games
when shopping to give them that new
look.
The control panel on early
"Robotrons" can come loose. Changing
the position of the side bracket will
eliminate this. The panel was loose on
a few early games. The brutal action of
the game would loosen the panel
further.
The attract mode can be
programmed with a message on two
lines. This is an excellent feature to
insert the location name. Williams'
game adjustments are the finest in the
industry.
The games must be tuned to the
location for maximum earnings. As an
example, the difficulty setting may be
set to 2. They were originally shipped
on 5, which was too difficult. Be sure
and watch your playing times. They
should get around at least a 2-minute
game to date.
As happens in this industry, there
has been a sleeper from time to time.
Last year it was Atari's "Centipede".
Earlier this year, it was Stern's "Tut"
and today it is "Moon Patrol".
"Joust" is my number one game in
every location. It has a definite advan-
tage of being a two-player game, one-
third of the money is generated with a
second player.
000
MIDWAY
"TRON" LIMITED BUY-IN FEATURE
This feature enables the player to continue his game by inserting an additional
coin before the timer runs out. He has this option only until he completes the third
phase of the game (Basic).
Option switch no. 1 at location B3 on the sound 1/0 PCB controls the Buy-In
Feature.
Switch #3 ON, the Buy-In feature is allowed and switch #3 OFF, the Buy-In
feature is not allowed.
STAR*TECH JOURNAL/DECEMBEtMNUFACTs
O
7
ATARI POWER-ON RESET AND WATCHDOG CIRCUITS
By Frank Becker, Atari, Inc., Somerset, NJ
The purpose of the Power-On Reset Circuit is
to hold the reset line to the MPU low until the
power supply five volts stabilizes. This will
insure that only valid information is present on
the address and data lines when the MPU is
initialized.
The OP-AMP RS is configured as a differ-
ential input or difference amplifier; this means
it amplifies the difference between both input
pins. In analyzing this particular circuit, we see
a voltage divider network consisting of resistors
R69 (22K) and R72 (lOK) tied to 10.3 volts.
This produces approximately 7 volts on Pin 3,
the non-inverting input, when the 10.3 volts
reaches its maximum value. The inverting
input, Pin 2, has 5 volts applied to it.
Looking at Figure 1, we have 7 volts on the
positive input and 5 volts on the negative input.
We then perform more simple math to find out
if the differenc between the inputs is positive or
negative. 7 - 5 = 2. Because the difference
between the inputs is positive, the OP-AMP's
output will try to go as high as it can; however,
it will be limited to the OP-AMP's positive
power supply which is 10.3 volts. If the difference
had been negative, the output would have gone
as far negative as possible, in this case only
down to ground.
To summarize the operation of the OP-
AMP in this configuration, it can be stated that:
If the difference between the inputs is
positive, the output will be + Vee.
If the difference between the inputs is
negative, the output will be - Vee.
Refer to Figure 2 on page 8. You might now
expect to find the output of RS Pin 1 at 10.3
volts, and you would if it wasn't for the 220-
ohm resistor R73; R73 keeps the output at
about 5 volts. Diode CR3 protects the input to
F7 by clamping the input at 5 volts, should the
OP-AMP's output rise above 5 volts.
The output, Pin 1, will then be 5 volts
except during power-up. During power-up the
output will stay low for a very short time to
allow the five volts to stabilize. This occurs
because the resistor values of the voltage
divider are chosen to insure that Pin 3 never
goes higher than Pin 2 until the 5 volts stabilizes.
(Continued on next page.)
10k
Figure 1
68k
220A.
R72
22k
m
m
10.3
7v
R69
Vout
5.0v, >-----2---1
TO HAVE
T.
MODEL 125 • ARCADE JOYSTICK
The only sensible replacement
• manufac;tured from aluminum stru
• all mechanical fasteners of aircraft ty
• contact plates made of STAINLESS S
• gold contact points
• 2,4, or 8 positions
This unit ~ designed to give you and your
joy possible.
NEWPORT CONTROLS
7330 ADAMS STREET
PARAMOUNT, CA 90723
(213) 633-4494
®

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