Hi all, just picked up this Asteroids cabinet, never dealt with a vector monitor before, and this is what I'm getting on the screen, where should I start?
Asteroids Pickup: Need help with the G05 (Tiny Objects)- SOLVED
- Thread starter OrangePeel
- Start date
87 t-66
Well-known member
What does it look like on your scope?
OP
OP
I've got a couple vintage scopes that I need to test and get probes for.
andrewb
Well-known member
Use the advanced thread search page here and search for your monitor type and issue. This problem has been covered before in many threads.
wugly
Well-known member
If its not resetting and you are in test mode then you are probably good on the cpu side. the game is not issueing a tone telling you you have faulty ram. the state machine is drawing an image with multiple lines so your state machine is mostly functional. program is not crashing so probably got past vector program counter which leaves us with something in the vector counter going out to the dac chip but I would focus on looking for a problem in and around the vector counter and on its way to the dac. this is agood starting point and when you solve this problem it will reveal if you have further problems. maybe something on the z axis
OP
OP
Got it resolved! Had to replace the LS7404 at position H10, and re-flow some headers.
Rev. 04 board for future reference.
Still not running perfect, I believe it needs a recap too. The vectors aren't being drawn completely straight, and it seems to crease slightly along the center, but it is playable now!
Rev. 04 board for future reference.
Still not running perfect, I believe it needs a recap too. The vectors aren't being drawn completely straight, and it seems to crease slightly along the center, but it is playable now!
andrewb
Well-known member
Is that picture correct? (Or is it just showing one of the asteroids exploding?) Are you getting different sized asteroids?
Also, post a pic of the test screen crosshatch.
OP
OP
All the objects look correct, the game is running correctly.
andrewb
Well-known member
Cool.
I was asking because of your comment about 'not all vectors being drawn straight'. You can adjust the size and linearity on the deflection board to get those crosshatch lines straighter. The trick is to not look at the lines, but look at the heights/widths of the diamonds. Linearity controls the size, but just for the outer 3"perimeter of the screen. So if you iterate adjusting all 4 controls, you want to get the heights and widths of the diamonds to be consistent across the X and Y directions of the screen.
Once you do that, the lines should come out straight. (Or pretty close.) Sometimes it takes a bit of iteration to get them 'perfect', and on some systems you won't get 100% there. But close is good enough. As long as they're close, the objects on screen won't warp and change size as they travel the screen. As long as that's the case, you're all set.
I was asking because of your comment about 'not all vectors being drawn straight'. You can adjust the size and linearity on the deflection board to get those crosshatch lines straighter. The trick is to not look at the lines, but look at the heights/widths of the diamonds. Linearity controls the size, but just for the outer 3"perimeter of the screen. So if you iterate adjusting all 4 controls, you want to get the heights and widths of the diamonds to be consistent across the X and Y directions of the screen.
Once you do that, the lines should come out straight. (Or pretty close.) Sometimes it takes a bit of iteration to get them 'perfect', and on some systems you won't get 100% there. But close is good enough. As long as they're close, the objects on screen won't warp and change size as they travel the screen. As long as that's the case, you're all set.
OP
OP
Yeah i think it's good for now, the asteroids and ship aren't warping when they move, so I'm satisfied for now, thanks for your help!
