Asteroids Tech

[Guests]

[ukvac] Asteroids Tech
Hi Guys,

Curerently repairing an Asteroids and theres a problem thats been
bugging me...Although its mostly playing ok

I'm getting a spot in the middle of the monitor "most of the time",
although the rest of the display is fine....If I turn the
brightness/contrast up, I get a bright dot (duhh !! yer), If I turn
it right down, so that everything else dissapears, I get a very faint
glow still....

If I set the controls up for the game itself,as best as I can, I'm
getting a reasonable glow which is a bit distracting and about the
size of a small asteroid.

Now there is a bit of a spot burn on the monitor (no great shakes)
and I thought initially that it was down to this eg.. the phosphur
being a bit damaged or something.... BUT When I go to "High Score
Name Entry" , the spot moves to the bottom left of the 1st A letter.

I've tried 2 Deflection Boards, both the same problem, as I thought
initially that it might be a Z blanking issue.

Is this a common fault, or a "Standard feature" of this game ?

Alternatively I'm "guessing" that there could be some kind of fault
with the vector generator (I'm getting the other common fault of
asteroids sometime explode with a line problem which I plan to repair
soon).

Hope someone can suggest a remedy for this...This is the first vector
game that I've ever worked on, so I'm a bit unfamiliar with them..

Thanks, Regards, Colin

 

[MarbleMad]

Re: [ukvac] Asteroids Tech
do you have a problem with your Z output?
do you see any contrast between the light objects and the dark objects?
---
James G Watt
http://www.kinetic-arts.co.uk
Science is not an exact science.

 

[guddler]

Re: [ukvac] Asteroids Tech
Someone like Steve (Coule) will be far more qualified to come up with a suggestion for you than me, but first up i would try using a scope as a display (in XY mode) and see if you get the same spots appearing.

Will confirm one way or another if it's a board fault or a monitor fault...

Martin.

 

[Guests]

[ukvac] Re: Asteroids Tech

Yes..

The asteroids are faint ish... your ship is bright... I get the Grey
Banding Stripes on the test screen too...So I would assume that its
ok.

Ta, Col

 

[eggwheatis]

Re: [ukvac] Re: Asteroids Tech
Tried backing the brightness off till the dots disappear then turning the contrast up to get the right level?

Phil.
Colin Davies <colin.w.davies@btopenworld.com> wrote:
Yes..

The asteroids are faint ish... your ship is bright... I get the Grey
Banding Stripes on the test screen too...So I would assume that its
ok.

Ta, Col

 

[MarbleMad]

Re: [ukvac] Re: Asteroids Tech
i got a problem like that with my battlezone cab. In the end it turned
out that the monitor spot killer circuit was malfunctioning - killing
the Z signal BUT the monitor brightness was turned up so high you could
see the vectors anyway. The contrast was greatly deminished so you could
see the game and the central dot which is slightly brighter than the
invisible construction lines that you can sometimes see if the
brightness is WAY to high.

I'd check your spot killer isn't activating - see if the red LED on the
monitor deflection board isn't lit.

also check it IS active if you disconnect the asteroids board.

if that looks like a problem you can quickly disable the spotkiller by
removing the led.
---
James G Watt
http://www.kinetic-arts.co.uk
Science is not an exact science.

 

[Guests]

[ukvac] Re: Asteroids Tech
Yes, That was pretty much one of the first things I did once I got
the game ticking over and the display running.

Theres always a bit of background glowing blob in the middle of the
screen, even with the brightness and the contrast backed off, which
is why I thought that it may have been down to a tube fault, but
noticed that on the high score part, the glow in the middle
dissapears, so my gut feeling is that its game board related.

As I said, I'm a vector vigin, so I'm unsure what to expect.

Cheers, Colin

 

[Guests]

[ukvac] Re: Asteroids Tech
I also thought that.... BUT as far as I can tell, the spot killer is
working.. well the led comes on with no signal anyway

I know this as there was a problem with the video invertor circuit
drifting about, so I hardwired/forced it to upright mode (by removing
both transistors and shorting out one of the collectors to
emmitters). This fixed one fault where I was getting little or no
video which was very very crumpled up in one corner.

I've tried 2 deflection boards, 1 borrowed and 1 bought and repaired
(dry joints and a capacitor).... Is it likely that they would both
have the same fault ? (using the same HV unit I may add)

Thanks, Colin