DEFENDER proto restoration and troubleshooting

vernimark

Member
Joined
Sep 4, 2003
Messages
108
Reaction score
4
Location
Novate, Milano, Italy
Hi all,
i'm restoring a defender proto; i'm in a good point but plugging a defender white label boardset bought from quarterarcade I can see a broblem. no, 2 problems :)
boot operations are ok but graphics is corrupted on the top (few pixel lines ) and on the right side (more or less 10 columns). Here you can find a movie (movie is mirrored)
http://www.youtube.com/watch?v=5oYbGTR1x2s
changing rams 4116 the problem is always the same and nothing changes
do you have any idea? this is my first williams boardset so nothing is obvious for me.

thank you,
vernimark
 
Last edited:
Try adjusting your screen out. If my memory serves me correctly, thats just scratch RAM that is present on most Defenders. You should be able to expand the picture out and clip those parts off.
 
The pixels on the left side are scratchpad RAM and the flickering at the top is overscan (underscan?). Both are normal. Go to the diagnostic screens and there is a hash screen as part of the video tests. You can use that to adjust the image on screen to maximize the viewable area and minimize the edge effects.

ken
 
Back
Top Bottom