RE: Omega Race problem.

I had the same problem with a cine board. The reason was a faulty 74194
(shifter) in the arithmetic unit.

These things happen when there is a bad calculation of vector position for
some bits only. Try to understand if vectors are scrambled changing only X
or Y position.

Regards,

Marco

  _____

From: owner-vectorlist@vectorlist.org
[mailto:owner-vectorlist@vectorlist.org] On Behalf Of John Robertson
Sent: mercoledì 26 dicembre 2012 22.46
To: vectorlist@vectorlist.org
Subject: Re: VECTOR: Omega Race problem.

Lewis D'Aubin wrote:

Its under 'omega race strange issue'.. But I never got a reply.. Is there a
different area that handles even or odd bits off the spinner or something
along those lines?

I really don't think it's the spinner decode circuit; this happens in
attract mode as well.

I believe it's a RAM issue, but I don't have the schematic drawing either...
anyone got any ideas?

                                                                -Lewis

> Here's a short movie showing what it's doing:
http://youtu.be/SYn24St00XQ

Schematics are considered essential for fixing these sort of
problems...("Hey buddy, wanna buy an original manual?")

What you have is something is wrong in the Negative X and Negative Y vector
rendering. If you watch your ship only when it is turned in the area between
6 & 9 O'Clock do you have the problems.

This is unlikely to be the image Eprom as the image is correct for the other
three quadrants and all that is tucked away in the image Eprom are three or
four images for the ship as rotated from horizontal to 45 degrees. After
that everything is done with the electronic equivalent of mirrors...

Not having time to do the troubleshooting for you at least these clues
should help you narrow down the part of the circuitry that is responsible.

Good hunting!

As for schematics have you checked
http://www.cityofberwyn.com/manuals/index.htm? (seems real slow today)

or KLOV.com

http://www.arcade-museum.com/game_detail.php?game_id=8920 (yup, there is the
manual in PDF...)

John :-#)#

-- 
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
                 www.flippers.com 
"Old pinballers never die, they just flip out"
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