Play Meter

(continued from previous page)
ill J::'l, 'C ~ '1?'-.:
PUI'-IER
•
MEMBER
Volume 2/ No. 15
December, 1976
staff
Publisher and Editor:
Ralph C. Lally II
Managing Editor:
Richard S. Dietrich
International Editor:
David Snook
Editor, Coin Slot
Technical Editor:
Robin Minnear
Head Instructor, Kush N' Stuff
Correspondents:
Roger C. Sharpe
Thomas Borden
Timmothy Jarrell
Dick Welu
Mary Claire Blakeman
Michael B. Klein
Circulation Manager:
Carolyn 0 . Desmond
Production:
Earl Dupre
Hellen Seal
Carol Lally
Typography:
Skybird Typography
Advertising Representative:
Ralph C. Lally II
Published monthly by Skybird Publishing
Company. Publishing offices 4136 Wash-
Ington Avenue, P.O. Box 24170, New
Orleans , La . 70184 . Telephone (504)
827 -0320 . Printing Offices, Franklin Print-
ing Co ., 209 Magazine St., New Orleans,
La . Controlled circulation at New Orleans,
La . Subscription rates: U.S. and Canada--
$20; Europe and Japan -- $35; Elsewhere--
$40 . Multiple subscriptions (ordered at one
time) : 2-9, $17 each; 10-24, $15 each; 25 or
more, $10 each . Advertising rates on
request. Copyright 1976 by Skybird Pub -
lishing Company. No part of this magazine
may be reproduced without express
permission. The trademarks, PLAY
=z: METER and COIN INDUSTRY PLAY
~ METER , are registered . The editors are not
for unsolicited contributions .
~ responsible
Postmaster : Send form 3579 to Play
~ Meter, P.O. Box 24170, New Orleans, La .
~ 70184 .
2
Bank of Chicago as secured parties.
Prior to the sale, Chicago Dyna-
mics President Jerry Marcis told
Play Meter that he expected bids to
be made and the company to be
back in business on a full-time basis
shortly. Currently Chi Coin em-
ployees are on a temporary lay-off
and production is shut down.
Current models are bing shipped,
however, according to Marcis.
The bank made the only bid on
the assets, however, and their bid of
1.8 million was accepted. In a later
conversation with Play Meter, fol-
lowing the sale, Marcis indicated
that that figure was a rather
misleading one in that certain
property of the company, including
its real estate, had been excluded
from the sale.
As Update went to press, the
bank was negotiating with a pro-
spective buyer, which Marcis could
identify only as "a well-known name
in the industry." A sale announce-
ment is expected shortly.
Chicago
Considers
Pinball Law
Chicago's City Council met early
this month for a second hearing
regarding a proposed ammendment
to the decades old ordinance licens-
ing coin-operated equipment in the
city of Chicago. The ammendment,
proposed by Mayor Richard J.
Daley, would change the ordinance
to allow the operation of flipper
games in Chtcago.
The council heard testimony from
Joe Robbins of Empire Distributing
of Chicago. Later Robbins told Play
Meter that his testimony in favor of
the ammendment met with a good
reception from the council although
he did hear many of the usual
negative comments about the coin
industry and he felt that the council
was laboring under some misunder-
standing with regard to the income
earned by the average pinball game .
The ammendment was referred to
the council's finance committee for
further study. While this may delay
matters slightly, Robbins declared
that he thought the ammendment
had a "better than fighting chance"
to pass.
TELHI';'HLflL
l[]P~LE
by fred McCord
I have received requests for credit
and start circuit rundown, so, here
goes .
Figure 1 is a typicat credit and
start circuit.
Figure 2 is a typical electronic
latch circuit.
This circuit is commonly called
the static circuit because of the role
it plays in turning off the game if a
static charge is introduced into the
game.
First, let's go through the logic in
Figure 1.
1 A coin is dropped in coin slot
and coin switch makes and breaks.
7404 prevents normal switch
switch bounce from getting into the
logic as erroneous pulses .
2 . Logic "~" on 86 pin 3 is
inverted and puts a logic "1" on
A7(7474) pins 1 and 13. (Pins 1 and
13 are the direct reset pins of DC flip
flop. A logic "fl" (bubble) prevents
the inputs from affecting a change
at the outputs, and forces Q(pin 5)
to a ",£5" and
(pin 6) to a logic
, 1 , . )
3.
A7(7474) comprises an
anti-cheat circuit which prevents a
credit due to incidental or player-
induced vibrations . Pins 1 and 13
must be high ( 1) for a period of time
equal to or greater than 128 vertical
pulses or about 4 milliseconds.
4. If the coin switch is made for
the required length of time then
both "Q" outputs (pins 5 and 9) will
go high .
5. Pins 1 and 2 of 7408 both going
high at the same time cause a high
output on pin 3.
6 . This high goes to 7404 pin 11
and IS inverted . The resultant low
clears (resets) flip flop 87 .
7. Wh en a 7474 is reset its 0
output goes high and the result is a
logic low at 7402 pin 12 which
ii ll ows c urrent to flow through the
crucllt LED thu s illum1n.1 ting it .
8. M eanwhile th e same logic high
th at en noes to pin 11 of the 7402 (C6) .
Note the configuration of the 7402 is
such that output is low (bubble)
when either input is high (no
bubble) . Since a high on C6 pin 11
n