Inconsistent Pac-man Patterns in MAME

General discussion on MAME, MARP, or whatever else that doesn't belong in any of the other forums

Moderators: mahlemiut, seymour, QRS

Post Reply
D_Harris
Button Slapper
Button Slapper
Posts: 11
Joined: Mon May 26, 2008 8:55 pm

Inconsistent Pac-man Patterns in MAME

Post by D_Harris »

I've been testing out some new strategies on Pac-man and ran into some anomalies. Once in a while the game will briefly freeze and some times skip ahead. I assume that this may be because of processes running in the background.(Though I have nothing running that I can tell).

A bigger problem is in the game play itself. If I run a pattern about ten percent of the time something different will happen. And I'm talking about a pattern that works as good as 100 percent of the time on the arcade platform. But in MAME the relative distance of Pac-man from the monsters at any given point in the maze just will not remain consistent from one identical maze to the next. (This of course causes the pattern to break).

Does anyone know the reason for this? Is this a MAME bug?

Thanks a lot.

Darren
User avatar
Chad
Tournament Coordinator
Posts: 4463
Joined: Tue Mar 05, 2002 3:15 pm
Location: calif

Re: Inconsistent Pac-man Patterns in MAME

Post by Chad »

the first point is probably machine related and not emulation, keep the F11 view open and you should be able to count frames when emulation is running and see the counter stop if the machine is taking over and doing something else while the emulation pauses.
-skito
D_Harris
Button Slapper
Button Slapper
Posts: 11
Joined: Mon May 26, 2008 8:55 pm

Re: Inconsistent Pac-man Patterns in MAME

Post by D_Harris »

Chad wrote:the first point is probably machine related and not emulation, keep the F11 view open and you should be able to count frames when emulation is running and see the counter stop if the machine is taking over and doing something else while the emulation pauses.
I figured as much. But it's the pattern breaks that are the big problem.

I know it's not my control panel because it is the same control panel taken off of my machine and connected to a controller.

Thanks.

Darren
User avatar
LordGaz
MARP Knight
MARP Knight
Posts: 220
Joined: Sat Mar 09, 2002 5:07 pm
Location: London, UK

Re: Inconsistent Pac-man Patterns in MAME

Post by LordGaz »

If there's a pattern break then you haven't followed the pattern pixel-perfectly by not turning into corners before you reach them etc. Or maybe your machine decided to 'freeze' for 1 or 2 frames while you made a turn which would break the pattern, this is what happened to me in my split screen attempt which is on MARP.

You could also frame step with shift-P through recordings where the pattern breaks and investigate more closely. MAME used to be able to display the frame-count which would help while stepping through but I can't find this feature any more.
User avatar
The TJT
MARPaholic
MARPaholic
Posts: 2479
Joined: Wed Mar 06, 2002 10:56 am
Location: 20 Grand Palace

Re: Inconsistent Pac-man Patterns in MAME

Post by The TJT »

LordGaz wrote:If there's a pattern break then you haven't followed the pattern pixel-perfectly by not turning into corners before you reach them etc. Or maybe your machine decided to 'freeze' for 1 or 2 frames while you made a turn which would break the pattern, this is what happened to me in my split screen attempt which is on MARP.
That's probably the reason...because other players can duplicate pacman patterns.
Of course if you still think it's mame, you can try some other mame versions known to work with pac-terns.
Hard to imagine that the relative speed of ghosts would be different to the speed of pacman's since both are defined by mame and roms used, right?
I'd rather think that if emulation is off then both the monsters and pac would move more slowly or faster than the original...but still same speed relative to each other.

I had a thought that it could also be Darren's joystick interface hack(ps2/usb etc) having lag in execution compared to original. Having the original stick doesn't mean that the circuitry where the stick is hacked to has identical timing to arcade hard/software.
The feel and accuracy of my Star Wars yoke hack is far from arcade because of USB/driver/Windows problems.

But yeah, the freezing effect can certainly screw your timing. I sometimes have the same problem when antivirus program kicks in downloading updates. Or during HD operations such as writing the inp during gameplay.
Post Reply