Hey-
I finally got a Marble Madness up and running (almost).
The game plays through and responds to controls.
Sounds/music are fine
EPROMS all check out fine with a burner
It has some screwy graphics problems though.
First of all, the blue ball doesn't show up. If it falls, then the graphic of it reappearing shows up, but when the ball is on the playfield, it is invisible. You can control it and even make it to the end of maze 1 by watching where it reappears and playing blind.
The red ball shows up, but the trakball has a bad axis.
The mazes are missing a bunch of detail.
Most of the top of maze one is black. Maze two is missing a lot of vertical pieces, but most of the paths show up.
The board I'm working with is a TTL type. I was focusing on the graphics ROMS (chips E3-E12, D8,D10,D12).
All of the address lines at those chips ohm-out the same across chips.
All of the data pins at chips within a graphic plane (0-4) appear common across chips too.
Both the address and data lines appear to be properly pulled-up to +5V through the resistor packs.
I focused on the graphics chips, suspecting crappy sockets, but am not finding proof of that.
I tried simulating the issue in MAME by substituting ROM files filled with FF's or 00's, but can't get the same stuff to show up.
I think the correct Slapstik is there (103).
I'll try to snap a photo or two when I'm with it next.
Any pointers appreciated.
I finally got a Marble Madness up and running (almost).
The game plays through and responds to controls.
Sounds/music are fine
EPROMS all check out fine with a burner
It has some screwy graphics problems though.
First of all, the blue ball doesn't show up. If it falls, then the graphic of it reappearing shows up, but when the ball is on the playfield, it is invisible. You can control it and even make it to the end of maze 1 by watching where it reappears and playing blind.
The red ball shows up, but the trakball has a bad axis.
The mazes are missing a bunch of detail.
Most of the top of maze one is black. Maze two is missing a lot of vertical pieces, but most of the paths show up.
The board I'm working with is a TTL type. I was focusing on the graphics ROMS (chips E3-E12, D8,D10,D12).
All of the address lines at those chips ohm-out the same across chips.
All of the data pins at chips within a graphic plane (0-4) appear common across chips too.
Both the address and data lines appear to be properly pulled-up to +5V through the resistor packs.
I focused on the graphics chips, suspecting crappy sockets, but am not finding proof of that.
I tried simulating the issue in MAME by substituting ROM files filled with FF's or 00's, but can't get the same stuff to show up.
I think the correct Slapstik is there (103).
I'll try to snap a photo or two when I'm with it next.
Any pointers appreciated.

