How do you play Impossible Mission?

[Doc4]

I can figure out what the heck is going on in this game. Anyone wanna help? I found nothing and ran all over the place, I can't find any clues or passwords to shut the stupid robots down. It's driving me nuts.

[MattyXB]

I have hear, that the NTSC version can not be finished. It has a bug.

Only the PAL version can be finished. But I have never try it.

[Cybergoth]

Hi there!

 

You'll find more than you ever wanted to know about Impossible Mission on my Epyx Shrine. Included are the manual, strategies to solve evry single room, an example of how to do the puzzles and even interviews with some of it's programmers.

 

And don't forget to submit your Hiscores...

 

Greetings,

Manuel

[+Marc Oberhäuser]

The C64 version rules. It's such a great game!

 

Marc

[zanza]

I agree totaly with MaO

 

I have played endless hours on my C64 and If I remember well, it was the first talking game which I had on my belvoved Commodore

 

 

Instant classic

[Mayhem]

Must be good... it's the only non-UK game in my top 10 C64 list

 

Not impossible, but a damn good game...

[bangles66]

Yes the 7800 version has a bug so it is IMPOSSIBLE .

Still a fun game to play around with.

 

I should add the NTSC version is IMPOSSIBLE.

Not sure about the PAL version.

 

[ 03-24-2002: Message edited by: bangles66 ]

[Mayhem]

PAL version is fine, as I've completed it many times. It is actually harder than the C64 version because the leeway on jumping over the robots is a lot smaller...

[Tempest]

Why doesn't someone hack the PAL Impossible Mission to NTSC like Sentinel? I'd like to be able to play it some day and win!

 

Tempest

[+Propane13]

I don't think that 7800 PAL sentinel was hacked to NTSC. I'm pretty sure that the "new" carts are copies of the NTSC Sentinel prototypes, burned on an EPROM and put in PAL Sentinel cases.

 

Also, converting PAL to NTSC and vice versa on a 7800 is quite non-trivial. I remember testing PAL Imp Mission and PAL Sentinel on my hacked-BIOS 7800 (no enryption check), and it didn't look right on my screen, due to too many Display List Lists, and timing was off (I believe it was 2x slower than normal).

 

-John K. Harvey

[Tempest]

I wonder if it would be easier to just try to find and fix the bug in the NTSC version? Could a code comparison between the two versions turn the bug up easily?

 

Tempest

[+Propane13]

Maybe, maybe not.

 

The bug itself is rather complicated; puzzle pieces can be hidden behind terminals. I doubt there's an easy way to fix this problem with just a few instructions added or subtracted.

 

I bet it's table-driven. It's not random-generated room-layouts; it's definitely pseudo-random. If you power on Impossible Mission, and make a map of the puzzle pieces and other items, then power down, wait 5 minutes for everything to return to a stable state, and repower it up, then behold-- it's the exact same level. So, my guess is that each room has a number of puzzle pieces that can be added to it, and a matrix of which devices to hide them behind is generated on a room-per-room basis, dependent upon which pseudo-random configuration is set up. To remove such an error, the table generation routine would have to be fixed, such that it will NEVER assign pieces behind the terminals.

 

This could cause all sorts of problems-- what if extra code to filter this fills a bank of code? Then things will have to be moved around to compensate, which causes a big headache.

 

I do agree that it's potentially beneficial to look at the PAL vs. NTSC differences, if the difference is something simple. However, a lot of sleuthing would have to be done to isolate NTSC vs. PAL code. Does the PAL Impossible Mission ROM exist somewhere?

 

I do know that the ending sequence exists in the NTSC version, so at least Atari *thought* it was finishable when it was released

 

-John K. Harvey

[+Mitch]

If anyone is interested in playing with the PAL ROM I have posted it here.

 

Also, from what I recall, pushing up at a terminal shows the same menu as the NTSC version.

 

Mitch

http://atari7800.atari.org

[Doc4]

I didn't see anything related to impossible mission at the epyx shrine, where is it! This game is getting less fun everytime I play it. I can't seem to do anything!

[Agent X]

When you press up near a terminal, you access the computer (in order to reset the lifts or freeze the robots temporarily). When you press up near another object (such as a piece of furniture or a vending machine), then you search it for puzzle pieces.

 

The bug in the NTSC 7800 version is that it hides some of the puzzle pieces behind the terminals. Since you can't perform a search of the terminals for puzzle pieces, you can never gain those pieces, and therefore cannot successfully complete the game.

 

Ironically, I remember someone writing a letter to Atarian magazine about this bug, and the response insisted that the person must have missed something.

 

It's too bad this bug exists, because otherwise I would have considered this to be one of the top 7800 games. The Commodore 64 version, which I was able to complete (since it does not suffer from this bug), is one of my favorite 8-bit computer games ever.

[Tempest]

Is the bug that pieces weren't supposed to be hidden behind terminals, or that the terminals can't be searched?

 

Tempest

[+-^CrossBow^-]

They way I read it...is that the pieces can be found...but for some reason the last piece is always hidden behind a terminal somewhere and hence the game says nothing there when you search the terminal. However, I have played the NTSC rom and found it odd that I never found a single piece...so maybe that is the problem in that the pieces are all behind the terminals and hence never show up when you search the terminals. Not sure...but I do remember something stating it was always the last piece that can never be found.

[+Propane13]

Good question. Both of them are the same bug, indeed, but I wonder which way they went with their resolution. My guess is they made it so that pieces can only be put behind non-terminals. This would be easiest, because pressing up in front of a terminal is the same as pressing up in front of a piece of furniture... just with different effects.

 

Anyone have the PAL version to verify what happens when you press "up" at a terminal?

 

I always thought it odd that such a glaring error was released. I mean, don't people play-test it? Perhaps the problem occurred with a last-minute software change that caused the problem to imminently occur, which happened after all of the play-testing was done. Anyone know?

 

-John K. Harvey

[Cybergoth]

quote:

---

Originally posted by Monster greifen an:

I didn't see anything related to impossible mission at the epyx shrine, where is it! This game is getting less fun everytime I play it. I can't seem to do anything!

---

 

It's in the "Games Rated A-D" section. Besides there should be a link on the main page near the 'Improbable Mission' news.

 

Greetings,

Manuel

[+-^CrossBow^-]

Okay...this all makes sense now. They programmed the game to basically reset the pieces randomly everytime you play the game. To do this easier they set it up to randomize behind virtually anything. This means that many times one or more pieces could be behind the terminals and hence unable to find them. But doesn't this also mean...that rarely the game might never hide any of the pieces behind a computer terminal? If so...then it may be possible that occasionally the game could be beatable?

 

Makes one wonder...but then it also means that somehow the fixed PAL version somehow differentiates the terminals from furniture to prevent the pieces from being hidden behind them.

 

We need Scott and Thomas's code sluething skillz to figure this out...

[Tempest]

I suppose its statistically possible that you could get a game without any pieces behind a terminal but I wouldn't want to overwork my noodle figuring out the odds...

 

Tempest

[Agent X]

I've played the 7800 version enough that I've searched every searchable object on several separate occasions (I would say at least 10). I even hit the Reset button a few times before starting to "randomize" the game (since it always starts off with the same layout if you don't reset the system). Every time, I've always missed at least 7 or 8 of the 36 pieces needed to complete the game.

 

It might be possible to get a game where all the pieces are able to be collected, but I'd say the odds are absolutely astronomical. If you want to play the game with the intent that you might actually complete it someday, then my advice would be to try to obtain one of the old computer versions instead.

[Inky]

I say heck with it an play the game Zillion on the Sega Master System. One of the few gems that system has..

[Cybergoth]

quote:

---

Originally posted by Inky:

I say heck with it an play the game Zillion on the Sega Master System. One of the few gems that system has..

---

 

Well, if you own a Sega Master System, you could as well play Impossible Mission on it.

I think the SMS version is awesome!

 

Greetings,

Manuel

[slapdash]

Well, does anyone have these numbers?:

 

1) # of pieces to be found

2) # of terminals

3) # of other furniture

 

If so, we could calculate the odds of success... (Well, I probably couldn't, but my brother probably could).