Pacman too fast?

It looks like maybe the 'game over' is two different colors too that might give you a hint to what area it's in.

i've seen Asteroids that they did like that on purpose, but never a pac-man. I doubt anybody would do it on purpose THAT fast anyways, that's crazy.

I'll bet it's something simple, I don't know what makes games speed up like that, for instance it may be it's just got too fast of a crystal in it, or the chip that divides the clock signal down isn't working right... I'm not sure if the clock signal running fast would do that though.

I'm sure somebody who understands the circuit would be able to fix that very quickly.
 
That's awesome. Post when you figure out what it is so we can make other boards play like that.
 
Maybe related to this:

pacpic.gif
 
in my early arcade living youth I saw Pac and Ms. Pac one of two ways: with the turbo chip to make Pac only fast and another where the entire game was sped up.

my grandpa was always a huge proponent for turbo.

I wanna say when I tinkered with the game in MAME there was a dipswitch to speed the entire game up. I can't tell for certain right now though.
 
Years ago, I bought a non-working MsPac board and noticed that one of the 161 counters had some pins lifted and jumper wires changing around a couple of signals. I recall reading about a hardware speed hack however I can't find it in any of my notes from a decade ago.
 
Got to mess around with this board a little bit tonight... First I have a spare Ms pacman board with some separate issues... So for test one, I pulled the pacman chips and added the MS pacman chips I had. Same issue... Except it's super fast Ms pacman.... So no solution on that board yet.

Next I decided to try the pacman chips on the now empty Ms pacman board... Works except see the attached pic... Having troubke navigating lawnmower man's page to figure out exactly what this problem may be... Does anyone have any suggestions?
 

Attachments

  • IMG_20170119_185032776.jpg
    IMG_20170119_185032776.jpg
    200.9 KB · Views: 31
For what it's worth on my Ms. Pacman I had a similar issue where the game was fast... not that fast but much more difficult. No chips were altered however solder was bridged across two packets...

Taken from my own blog..

I noticed during game play that the game seemed rather difficult. The Ghosts were not staying blue for that long. I was able to compare this against my MAME machine and my suspicions were correct. No dip switch settings on the actual PCB existed to change the difficulty or the ghost timing so after more research I was able to come up with a solution. Basically "There are 2 small solder pads near the DIP switch bank, right next to it is resistor pack RM6, the 2 pads are located just past the end of RM1 (by DIP switch 8) see if they are jumpered". Below is a picture of my board set and the cause of making the game more difficult or rather the ghosts changing quickly from blue back to normal. You can see the glob of solder right above RM6 (above and slightly to the right of dip switch bank), after I De-soldered that glob my game was playing as it should! hopefully this helps anyone else who thinks that their Ms. Pacman PCB seems like the ghosts are changing back too fast.

again that's Ms. Pacman...

105cqbm.jpg
 
I'll definitely check that but I think its more of some kind of timing issue... Even the game sounds are super fast... Like the intro sound when a game is started on Ms. Pac for example...
 
The "difficulty jumper" only adjusts the time the ghosts stay blue, afaik.
Your problem is the clock is running too fast. It could be a hardware hack or an issue in the clock circuit. I had a board doing the same thing once and it was just a shorted lead on the bottom side of the pcb.
I have come across the hardware hack a handful of times. It was how they used to speed them up before the speedup chip was made.
 
Back
Top Bottom