SEGA Master System level modifying

[Pooty]

Attached to this post is a tool you may use to create Master System Lemmings levels, along with its source code.

The tool included is not an actual level editor. It simply copies the ROM, then "injects" the level you designed using Mappy into the copy. You may download Mappy at http://tilemap.co.uk/mappy.php. Mappy is designed for Windows, but Linux users should be able to run it under Wine. It won't work on Macs, unfortunately. I need more programming experience before considering making a fully functional, portable level editor.

You can choose which level you wish to overwrite, but you can only overwrite one level right now. Also, the game will automatically modify some levels, such as Tricky 04, Tricky 21 (massively), Taxing 24, Mayhem 03, Mayhem 13, and Mayhem 27 (there are likely others). This is a "feature" of the game itself. I plan on updating this program to cancel these effects if you choose to overwrite those levels. Also, let me know if you find some others. That would be great. 

One other thing, and it's about the use of Mappy. The tile size is 8x8, the map size is 112x19, and the tilesets you need to use are included in the zip file. After you've designed your level, you need to go to Custom -> Export binary file. When asked about adjusting exported values, set it to 0.

That's all I can think of right now. Let me know if there's anything you need help with. Hopefully nothing along the lines of "This program doesn't work" or "My computer burst into flames after running your program". That shouldn't happen.

[Edit: Oh yeah. Don't forget to modify the leveldata.txt file. It should all be explained in the readme.]

[Edit 2: Updated the program to allow .mlm files to be used, which uses the same file format as within the ROM.]

[Edit 3: Lemming maps for the original game now available.]

[Adam]

Brilliant, just brilliant, Pooty!

[namida]

Hm, what modifications exactly? I can understand with some levels (especially Mayhem 13, as it's a repeat with slightly modified terrain)...

Also, on that note: Do repeats get replaced at the same time?

Finally, one suggestion that should be quite simple: Allowing importing of more than one level at a time (for level packs, etc).

[Pooty]

Hm, what modifications exactly? I can understand with some levels (especially Mayhem 13, as it's a repeat with slightly modified terrain)...

The levels I mentioned are all modified terrain. Tricky 04 has a terrain piece between the one-way wall and the end of the platform on the right that isn't actually in the level data (The same is true for Taxing 07, since it points to the same data). It's added during a process between pressing 1 to preview/2 to play and the level loading. I know where it happens in the ROM, so I'll update the program soon to counter this.

Tricky 21 cuts the top third of the level off, so unless your level is low enough, don't use that one.

Also, on that note: Do repeats get replaced at the same time?

Nope. The repeated levels remain completely intact.

Finally, one suggestion that should be quite simple: Allowing importing of more than one level at a time (for level packs, etc).

I really, really want to do this, but the ROM is very tightly packed, making it difficult to modify without breaking it. The only reason I was able to get the ball rolling is because there is a fairly large amount of empty space near the end of the ROM that I was able to take advantage of. Might be able to fit 2 or 3 levels in there. I need a deeper understanding of how the game works before I can affect the rest of the game.

Implementing repeated versions of the custom levels, on the other hand, is much easier, and far less risky. All it requires is changing a couple of pointers, and you're done.

[Adam]

Just about made a workable version of Save Me using this editor.. will keep everyone updated.

[ccexplore]

Wow that is awesome. I gotta get me an SMS emulator and Lemmings ROM one of these days......

[edit: hmm, looks like the tile nature of SMS levels means you might never get the final part of "Save Me" to work the way it's intended (it looks like you can just use blockers instead of build + block)]

[Adam]

Yup, that's a big issue with the SMS version - you're fixed to the 8x8 tiles, which makes doing the final part of Save Me pretty darn annoying.

Here's a video of Save Me in action..
Sega Master System - Lemmings Mayhem 29 - Save Me

[Pooty]

I have an idea on how to retain the spirit of the original puzzle. There are two tiles in the tileset that feature only one pixel; a pixel in the top-right corner, and a pixel in the bottom-left. They are part of the curved pillars. If you place one to the left side of the platform above the exit, and the other to the right of the platform the exit is on, you should be forced to use builders. It might look slightly odd (especially the one to the right of the exit), but it keeps the puzzle intact.

[Adam]

I've just tested that out, and unfortunately, the same problems still exist. Nice idea, though, and it does make doing the puzzle without builders a little bit harder.

[ccexplore]

Hmm, I kinda want to see it in action, what you said about your idea not working.

[Adam]

I'll quickly redo the level with the little single-pixel blocks to show you then!

[Adam]

Okay.. two videos here.

Firstly, as per ccexplore's request..
Sega Master System - Lemmings Mayhem 29 - Save Me (Backroute)

And secondly, here's Cascade..
Sega Master System - Lemmings Tricky 25 - Cascade

Enjoy!

[Pooty]

Ah, I see what's happened there. What I meant was to bring the metal platforms in line with each other, then do the modifications so that the left pixel tile appears next to the middle platform, and the right pixel is next to the bottom one (in other words, lower each pixel tile you set up to the platform below).

And nice work on Cascade.

[Adam]

Just tried that, Pooty - it definitely works, but, well, it ups the difficulty an awful lot.. even using the backroute, it's bloody difficult!!

[ccexplore]

For reference, in the "Save Me" on the PC etc. versions, IIRC the platforms are offset 2 pixels from each other.  So it's slightly more forgiving than Pooty's idea which is 1-pixel offset, but it was never totally easy to start with.  Does the controls on the SMS also make things harder, or is that not in play here?

Incidentally, I'm also curious:  while not the most useful move here, does the SMS has the same steel digging bug where if you decide to dig down at the specially placed pixels, it will take out the edge of the steel?  Or does the steel prevent digging?

[edit: sorry, maybe a better way to phrase is simply this:  is it possible to dig out a little bit of the steel edge, by building a little (or not) from the edge and then dig down?]