Ms Pacman too fast without speed hack

mgb

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I'm working on a Ms Pacman that is almost acting like it has the speed chip.
Ms Pacmans speed is real fast where the Ghosts seem to be normal speed.
I don't believe that the speed chip has been installed in 6F but the chip that is in there doesn't seem to have any markings.

I seem to remember reading something somewhere about this problem but I can't find that now. Maybe the chip in 6f is at fault??

Any help is greatly appreciated.
 
A friend of mine had a similar problem with a Ms Pac he recently picked up, turned out the harder difficulty option was jumpered. 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.
Rich
Green Bay
 
I'll try to get a quick video of it and I'll double check to make sure that something like the difficulty isn't set though it doesn't seem like increased difficulty because the increased speed seems to make it easier.
 
A friend of mine had a similar problem with a Ms Pac he recently picked up, turned out the harder difficulty option was jumpered. 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.
Rich
Green Bay

The difficulty jumper pad just changes the time that the ghosts stay blue. It may speed the ghost up (maybe?) but definitely not pac/mspac.

You probably have a speedup chip in it, thats what it sounds like. There is also a hardware hack but it speeds the whole game up since it basically increases the clock speed.
If you have an eprom programmer you could dump the rom and look at the data. You would have to actually look at the data since the checksum will be the same for speedup and regular.
 
The difficulty jumper pad just changes the time that the ghosts stay blue. It may speed the ghost up (maybe?) but definitely not pac/mspac.

Well, it does speed both the ghosts and Ms Pac up slightly. You speed up slightly on board 2, then again on board 5. Setting the jumper pad to difficult makes board 1 the equivalent of board 2 (on easy), and board 3 is like board 5 (on easy). But after that, they're the same, until you get to the slow boards. You slow down a few boards earlier on difficult. It's board 21 on easy (same as 9th key on Pac-Man), don't remember which one on hard.
 
A couple of things make me doubt that a speed up chip exists in this board because the people I am repairing it for have owned it since the early 80s and I can't really see when they would've installed it...., but I guess anythings possible.
I thought a speed up chip made both Ms Pacman and the ghosts faster but this board just seems to have Ms Pacman moving faster.
Unfortunately I have no way of readig the rom. I'm thinking of just getting another chip for 6F that is known to not be a speed up chip and see how it goes.
I'm still trying to locate someones repair log that I remember reading which said something about a problem like this. If I remember correctly it was caused by a bad rom (maybe 6f) or a resistance issue on one of the lines.
 
I thought a speed up chip made both Ms Pacman and the ghosts faster but this board just seems to have Ms Pacman moving faster.

No, the speed-up chip only speeds up Pac/Ms Pac, not the ghosts. You end up being the same speed as the monster eyes going back to the pen after eating one.
 
Oh ok. Thanks for the clarification on that. Well then I'm hoping its just that they had installed the speed up chip.
 
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