RE: TECH: Need Tempest Help Please!

Ta-da! I fixed my squiggley letters. After socketting/testing about half
the chips on the board, taking it from working with quiggley letters, to it
spouting out bad continuous tones, to resurrecting it to Mathbox errors
(with no problems with mathbox), to figuring out that I screwed up traces to
vector RAMS and the LS245s, back to where I started (working but with
squiggely letters) I had a revelation. The vector scaling section of the
board has some transistors. It just hit me. Those bad boys may be the
culprit. Now I had thought of those a long (and I mean a LOOONNNGG time
ago), but I had seen that they had already been replaced, so I assumed that
the transisitors were ok (yes, the I made an ass out of you and me move) .
This time, I just looked at them and said to hell with it... replaced them
with "known" working good ones... and voila. Perfectly functioning Tempest
boardset.
 
Thanks to all the people that have helped me through all of my troubled
times.
 
Cheers
Andy

-----Original Message-----
From: Kev [mailto:KKlopp@erols.com]
Sent: November 16, 2000 08:29
To: Evrovski, Andrew
Subject: Re: VECTOR: TECH: Need Tempest Help Please!

Andy,
 
Got a flaky Tempest board to work on myself.
 
I would do the desolder & replace method just yet. Do you have an O-scope
or atleast a Logic Probe?
 
Swapping the chips doesn't eliminate a bad socket either....
 
Good Luck & please post your findings!
 
Thanks,
Kev
 

Hey there...
 
    Thanks for the advice, but I had already swapped out different roms...
in fact, I have swapped out every socketed chip possible and everything in
the vid section... not any of those... I think it may have something to do
with the up/down counters in the addressing or a Tempest equivalent to the
Asteroids Deluxe Rate multipliers (LS191).... Anyway, I guess I'll work my
way back and track from the video out stage back through the vector state
machine and the X&Y outputs and de-solder every damn chip in each section as
I go and replace with a known working... damn pain in the ass, but what else
can I do.. :-)
 
Cheers
Andy

-----Original Message-----
From: Kev [mailto:KKlopp@erols.com]
Sent: November 8, 2000 22:59
To: andy@cyberplex.com
Subject: Re: VECTOR: TECH: Need Tempest Help Please!

 
Crazy Idea, but why don't you swap the game ROMs with your friend's working
board. I agree with your analysis that the characters are somehow corrupt &
possibly some on vectorlist can pop in with the exact differences on the
draw but I assume the playfield is drawn from RAM & perhaps the characters
are derived straight from ROM. Perhaps you have a ROM that is slow to
respond?
 
Kev

I am not sure where to go from here. It seems that perhaps it is only doing
this with textual characters and game draws because when I got to the test
screen, only the 0's are skewed (and the tempest spinner line).. the
cross-hatches, plus symbol, outline white box around the whole screens
appear fine... could this be a ROM problem?

The monitor is fine as my friend's working tempest board has no problem.

Any advice is appreciated.

Thanks

Andy

http://arcadeworks.halifax.cx/images/DCP00556.JPG
<http://arcadeworks.halifax.cx/images/DCP00556.JPG>
http://arcadeworks.halifax.cx/images/DCP00557.JPG
<http://arcadeworks.halifax.cx/images/DCP00557.JPG>

or

http://216.83.5.77/images/DCP00556.JPG
<http://216.83.5.77/images/DCP00556.JPG>
http://216.83.5.77/images/DCP00557.JPG
<http://216.83.5.77/images/DCP00557.JPG>

Andrew Evrovski
HPC Development Director
Cyberplex
t: 902.429.4721 ext.109
f: 902.423.0899
www.cyberplex.com

---------------------------------------------------------------------------
** To UNSUBSCRIBE from vectorlist, send a message with "UNSUBSCRIBE" in the
** message body to vectorlist-request@synthcom.com. Please direct other
** questions, comments, or problems to neil@synthcom.com.
Received on Sat Dec 2 01:33:56 2000