Glitch in Ms. Pacman for Mastersystem (Tengen)

[Elixir]

My mother's played this game (although not recently) for a really long time, probably over 10 years. Very rarely, I'd say it happened a total of about 10-20 times across these 10 years, the game would glitch up. As soon as she started a new game, instead of the dots being regular dots, the entire board would be filled with green energizers instead. They were still effective, and eating them kept effecting the ghosts.

I can't find anything online or any reports of this bug/glitch, though. What could have caused this to happen? I know it's a rare glitch but I don't know if it's something that hasn't been posted online before.

[BrianC]

I'm not sure what caused it, but it's possible the port was done by Tiertex since it's one of the games listed on their website and they didn't design any other version of the game (Tiertex games are often unpolished and glitchy). Also, Domark published most of the Tengen SMS games and I'm under the impression that they didn't design most of the Tengen licensed SMS games themselves.

Please no flak about this since I don't have concrete info. I assumed that it would be accepted that this was just opinion and not something I knew for sure, but this crap happened. What the heck is this crap? Even an admin does the internet thing?

[PC Engine Fan X!]

I'm not really too sure why this glitch appears in the SMS Ms. Pac-Man game. Could it have skipped past the beta testers and still released anyways?

On the Atari VCS (aka the 2600), you could insert any cartridge and barely flick the power switch to make some 2600 games do some weird shit. Take for instance, the 2600 version of Centipede, if you barely flicked the power switch, it was possible to start a game with absolutely no mushrooms on the inital wave and watch them crazy fleas lay 'em rapid fire style with your magic wand being able to move all the way to the top of the screen shooting those troublesome pests.

PC Engine Fan X! ^_~

[Specineff]

Could be just a bad cart, that one.

[Elixir]

Could be just a bad cart, that one.

I doubt it, this isn't the first cart of the game she had. See, she originally had the game in the 90's, sold it, and bought one many years later. Same thing happened. As to the cause, I have no idea. All I know is that it started from beginning a new session after having played through the game.

It's almost like an easter egg, but we don't know for sure.

[BrianC]

Could be just a bad cart, that one.

I doubt it since it was possibly developed by a company that often makes glitchy or unpolished games, and the fact that it happened with more than one cart.

I tried the SMS port of Ms. Pac-Man a bit more since that post at the sega8bit forums, and it seems like it could be a good version of the game. I'm on the fence about getting the cart, though. I heard it works fine on US SMS systems, but it doesn't seem to offer anything over the NES, SNES, or Genesis versions. I want to play some Ms. Pac-Man on my SMS, but I have the JP Opa Opa (aka Fantasy Zone the Maze), which is a nice Pac-Man style game.

[Specineff]

Ah, okay. It wasn't clear to me if it had happened with other carts before.

[D]

Please discuss this at smspower.org.
They probably know

[BrianC]

Please discuss this at smspower.org.
They probably know

It's a good site, but only a few posters. They know quite a bit, but not everything. I asked a question about Wonder Boy III not working on JP Mark III and SMS systems with the Tototek adapter and still haven't got an answer. I also asked a question on sega8bit.com's forums and not much luck in answers there either.

[Ixmucane2]

The glitch is reproduced on several carts, but did you test several consoles? The RAM, CPU, bus etc. in your mother's SMS unit might have defects causing a small but significant probability of random errors, perhaps only affecting the specific sequence and combination of memory addresses and data, flags and register contents, instructions etc. found at the start of a game of Ms. Pacman.

For example, there can be a memory location or register containing the type of object that is to be placed in dot locations and a timing error can flip one bit, or something of the sort, to write the code for "pill" instead of the code for "dot" there.
At this point the game would place pills in their proper locations and instead of dots too; if the game engine counts eaten items ignoring their type, simply sets invulnerability flags and timers when a pill is eaten, and doesn't freak out otherwise because there are less dots and more pills than normal, one can play with all pills without further errors. Other games would probably fail, but Pacman rules are simple and forgiving; for instance, ghosts don't care about dots and pills.

A console malfunction seems more consistent with exactly repeated but randomly occurring errors than a bug in the game: at game start, the only available data that could trigger or not trigger a deterministic bug are time elapsed and controller inputs (which one must go seriously out of his way to access, use unsafely, and turn into pills) and garbage left from previous games (plausible but not always present).

[Elixir]

Hey guys. I was digging through my Photobucket and found this from years ago:



This bug. As you can see, all the dots are energizers instead of regular dots.

I've seen it on various carts on various consoles.

[Mortificator]

It couldn't hurt to ask the tech-heads over at SMS Power.