Help with a Space Duel problem

Hi All,

I have a Space Duel board I'm trying to get running. It's works 99% of the
way but it has a really strange vector problem. On the opening screen of
Space Duel where there is the 5 + 4 squares (the S P A C E and the D U E
L), instead of looking like this...

S P A C E D U E L (invision little boxes around them)

it comes out like this...

S P E L

    A C E D U

And the first test mode screen with all the zeroes, the zeroes all slide
down off the screen at maybe one line per zero. In the test mode with the
alphanumerics, the sliding it more pronounced and the letters move down
faster.

My guess is that when the vector gun is turned off to jump to a new higher
location, the jump is somehow failing and the position is staying at the
same horizontal location. Then the guns turn back on to draw the next
vector, the position is wrong and doesn't get fixed until a center
instruction is hit.

Any ideas where the problem area might be? Does the DAC perform the
addition of the current position and the next position or is that logic
somewhere else? I don't see any adder anywhere in the vector circuitry.

Thanks for any help.

-Werner
Received on Tue Jul 21 12:00:28 1998