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