5
STAR*TECH JOURNAL/DECEMBER 1982
By Mark "Bear" Attebery, Vending International Corp., San Juan Capistrano, CA
Hello there fellow technical persons!
This is the start of a new technical column that I
hope you will find both interesting and informative.
I'm sure all of you are familiar with, and have
enjoyed, Todd Erickson's column, "On The Service
Trail", as it has been a regular feature in Star'11-Tech
Journal for some time now, and is extremely informa-
tive. In this new column I hope to touch on various
subjects that Todd doesn't cover such as: MOS/CMOS
integrated circuits, the care and handling procedures
required to deal with these highly efficient I Cs, and the
general characteristics of MOS/CMOS circuits. We
will also include reviews, modifications, and answers
to questions as we investigate microprocessor-controlled
arcade and vending machines.
If there are any games that you are interested in
knowing about, or that you have questions about or
have knowledge of (that you would like to share with
your peers in the technical field), just drop a line to:
ATTN: BEAR, Vending International Corp.,
33157 Camino Capistrano, Suite C, San Juan
Capistrano, CA 92675, or call 714/661-6608 and
let's talk about your ideas!
An example of the type of information I hope to
share with you is illustrated by the circuit modification
used on Bob's Space Racers' "Whac-a-Mole" game.
The problem with the game is that fibers from the
tickets used for plush redemption will build up on the
photo-optic sensor and won't let enough light through
to actuate the count circuit. When that happens,
tickets will dump out continuously and can spit out a
thousand tickets before a gameroom person can get the
keys and blow the lint or fiber away.
The easiest way to correct this problem is to
increase the amplitude of the light emitting section of
the photo-optic switch. This is done as follows:
1. Remove Resistor Rl and replace with a jumper
wire.
2. Remove Resistor R2 (330.n. ¼ watt) and replace
with a 330.n. ½ watt resistor
3. Remove Resistor R3 (87K ¼ watt) and replace with
a 6.8K ¼ watt resistor.
This will reduce the amount of maintenance time spent
each week, along with reducing the number of tickets
lost and unaccounted for. DO NOT use any form of
liquid cleaner on these optics! Even the "safe for
electrical components" cleaners may not be used. The
reason isn't electrical, it is thermal. The use of an
aerosol liquid on the light emitting section of a photo-
optic switch is like spraying a hot 100w light bulb with
cool water; it often results in a small implosion. Use a
fine brush or compressed air for cleaning these sensitive
photo-optic switches.
There are so many articles written in every publica-
tion you pick up now about videos that there isn't any
way you can review a game, or games, without coming
up with the same article as seven other columnists.
(For instance, when you've read seven write-ups on
Sega/Gremlin's "Zaxxon" at least five of them have
the same information.) So we are going to stick with
non-video equipment.
Once again, I would really appreciate a lot of input
from all of you Techs out in the field. That includes
suggestions for articles of interest to you, the Techni-
cian. It also includes your inquiries into various
problems you have run across, as well as quick fixes
for problems you have come up with, and want to
share with the rest of us.
Next month will include MOS/CMOS - Data,
Handling Information, Care and Maintenance. Also
included will be a write-up on Vending International's
"Fanky Malloon" Balloon Machines, and Namco of
America's "Shoot Away".
So, until next month, don't get your wires crossed,
and do get those ideals in the mail. Remember all those
times you wanted to tell everyone about a "fix" you
had come up with, but didn't have an outlet? Now you
do - so use it!!
THE
BUG
STOPS
HERE
LOGIC COMPARATOR $265
Performs in-circuit verification
of proper TTL IC operation
by comparison to a "known-
good'' IC.
Drive Motor Leads
Short R1
Replace with 330Jl ½w R2
Replace with 6.8K 1/4W R3
,-
mount screws
OUTPUTS
-------
Ticket count sw. (N.C.)
Orange
Ticket count sw. (N.O.)
Blue(D
®
1
INPUTS
I
I
Drive Motor and Logic v+_R_e_d@-=~--...J
Power Supply
GND Black@
I _ _
Motor Enable _ _ _ _ _ W.:..:.:.h:.:..:it=e~@~ _ _ _ _J
Figure 1
Bob's Space Racers "Whac-A-Mole" Ticket Motor Drive Board
SIGNATURE ANALYZER $395
Performs simple and
accurate in-circuit trouble-
shooting of RAMs, ROMs,
Microprocessors and other
complex ICs~
BUGTR4P™
INSTRUMENTATION
11 73 Tasman Drive
Sunnyvale, California 840B6
(40BJ 734-111 B
• The Signature Analysis Technique is licensed from
Hewlett-Packard Co.