John,

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

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

-----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.

3) Antenna? FCC regulation or something? Interesting.

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
www.QuarterArcade.com
Restored Arcade Games for your Home