TechTools Archives: RE: [techtoolslist] Pong

From: James Bright <james_at_quarterarcade.com>
Date: Mon Sep 29 2003 - 22:25:38 EDT

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John,

Thanks… this helps fill in the
gaps. Doesn’t look too, too hard…

JB

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--James Bright 
www.QuarterArcade.com 
Restored Arcade Games for your Home

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-----Original Message----- 
From: owner-techtoolslist@www.flippers.com
[mailto:owner-techtoolslist@www.flippers.com] On
Behalf Of John Robertson 
Sent: Monday, September 29, 2003
10:15 PM 
To: techtoolslist@www.flippers.com 
Subject: Re: [techtoolslist] Pong

Maybe not a crack wiz (not sure if I like that image ;-) but have fixed
a few in my time... 
 
At 08:00 PM 29/09/2003 -0400, James Bright wrote:

If I
remember correctly, John is a crack wiz with Ping boards (Am I right? Memory is
vague on this one). Figure Id try something a little different in the mean time
and look at a couple of non-CPU based boards J Ive got the
schems (no manual), so wanted to ask a few general questions. Ive included the
pinout that I have below for reference. I believe it to be the correct one. 
 
  
 
1) Im
guessing that I can just drive the board off of +5 and gnd and ignore the
xformer. Looking at the schems (they are *very*
fuzzy in the version Im looking at), that looks to be it. Guess Im half
thinking aloud here&

Yes, they generally all ran off ordinary +5VDC - took about 3amps AIR.

2) Monitor. I see a composite sync
line on the schems, but note explicitly documented in the wire diagram. But Im
guessing that you can just pick a color (or tie all three together) and just
run it into a normal monitor.

These games were usually B&W composite. Look for the VIDEO line, ground
being the other. Unshielded twisted pair ran up to the Motorola/Wells
Gardner/Ball Brothers monitor.

ANT was for forcing a reset on the board if someone tried to zap it for a free
play...it was a piece of wire about 18" long and if it picked up a spike
would clear the TTL registers.

4) Any
other gotchas? I was going to start playing around with it tonight during MNF.
I do have a Pong on hand right now, so I can also peek inside. Just much easier
to run the thing on my bench.

You can follow the image through the board if you make a Video Probe -
essentially a wire probe with a resistor (something like 10k) in series and
tied to the video input of the monitor. You can then visually trace the ball,
paddles, and clock circuits - The Book by ATARI is great for this
information - was up on Spies but I can email you a PDF of it. 
 
Paddles were usually 10K pots wired across the +5/ground so the wiper would go
from around 4V to around 1V - this was fed into a 555 that would change it's
output pulse length in accordance. 
 
John :-#)#

Pinout 
 
  
 
 1 transformer 
 
 2 
 
 3 
 
 4 transformer 
 
 5 
 
 6 transformer 
 
 7 
 
 8 +5 
 
 9 +5 
 
10 Coin NO 
 
11 
 
12 Coin NC 
 
13 
 
14 Paddle 1 
 
15 Ant (wtf???) 
 
16 Sound 
 
17 
 
18 Paddle 2 
 
19 
 
20 Video 
 
21 
 
22 Gnd 
 
  
 
  
 
--James Bright 
<a href="http://www.quarterarcade.com/" eudora=autourl>www.QuarterArcade.com</a> 
Restored Arcade Games for your Home

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Received on Mon Sep 29 20:13:27 2003

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