Lems and the Law

[StingRay]

Or, another idea as there is a WHDLoad installer for the game: Download the installer from the WHDLoad website and change the installer so that it just creates the diskimages somewhere in RAM: Then you can read from those images and everything should be fine. It would require a working WHDLoad installation but that shouldn't be a problem. As an added bonus you'd automatically support all Lemmings versions (as the WHDLoad coders did all the hard work already).

[Kinetic]

Originally Posted by StingRay

The problem is not related to the Copylock protection. Lemmings doesn't use standard disk format thus you can't read it without using the original custom loader. So again: Rip/Disassemble the loader from the game and you can read the disks/files. After all, the game needs to read its own files so there must a be a loader able to handle it somewhere in the game.

OK, apologies if it's I who have misunderstood you, but I think you might have misunderstood me. :-) I am assuming here that by "custom disk format" you are referring to the custom filesystem in use on the disks, instead of a standard filesystem understood by AmigaDOS.

I am aware that it uses a custom filesystem. I've known how this works for some time, and I already have a tool capable of extracting from and rebuilding disks in this format. When I say "I am unable to read from the original copies", I don't mean anything as naive as simply inserting them and being thwarted by their NDOSness. With the cracked ADF copies, I can happily read the raw data from the disk and get files out that way. But with the IPF disks, my (admittedly not extensive) attempts to read stuff have all thrown up errors. I have assumed that this is due to the Copylock.

Of course, the most ideal would be to be able to extract the info from the raw IPF data, from outside the emulator, the same as I am already doing with the ADFs.

I will go and look at the WHDLoad installer, though. (I've been using the other, JST-based HD installer for Lemmings :-)

[StingRay]

Originally Posted by Kinetic

OK, apologies if it's I who have misunderstood you, but I think you might have misunderstood me. :-) I am assuming here that by "custom disk format" you are referring to the custom filesystem in use on the disks, instead of a standard filesystem understood by AmigaDOS.

I didn't mean the custom filesystem, I meant the custom disk format. Those are 2 different things. =) I.e. the tracks on the Lemmings disk may have a different length/sync compared to standard Amiga DOS tracks (this is a form of copy protection). That's why there is a custom loader inside the game which is able to read these non-standard tracks.


Edit: and the IPF images are complete dumps of the original disks, with all the copy protection etc. left intact which is why you could not read them either.

[Kinetic]

Originally Posted by StingRay

I didn't mean the custom filesystem, I meant the custom disk format. Those are 2 different things. =) I.e. the tracks on the Lemmings disk may have a different length/sync compared to standard Amiga DOS tracks (this is a form of copy protection). That's why there is a custom loader inside the game which is able to read these non-standard tracks.


Edit: and the IPF images are complete dumps of the original disks, with all the copy protection etc. left intact which is why you could not read them either.

Right you are. That's kind of what I meant, but when I was saying "Copylock" I meant "the copy protection in general", as I wasn't aware the game used more than one kind.

Assuming I know nothing about the /physical/ details of disk formats, how does such a system get going? Presumably the bootblock is readable by the code in ROM and it then contains enough custom load code necessary to read the next stage from somewhere else on the disk?

[Hungry Horace]

havent got time to read the whole thread, but i am desperate for a Lemmings 1 level editor, in order to create more 2-player levels!

i hope this project might provide a solution. something that ripped the files, (use the imager slave from the WHDload version? if it uses disk images, then i know the JST install rips files!) then patched appropriately (like lemmings 2 editor) does seem a good solution to the copyright issues.

[StingRay]

Originally Posted by Kinetic

Assuming I know nothing about the /physical/ details of disk formats, how does such a system get going? Presumably the bootblock is readable by the code in ROM and it then contains enough custom load code necessary to read the next stage from somewhere else on the disk?

Yes, the bootblock is always the first place to check. It either already contains the custom loader or it loads the loader/mainfile among other things. So you'd disassemble the bootblock and see what happens. This is a very (very! ) simple explanation but I hope you get the point.

[Kinetic]

Originally Posted by Hungry Horace

havent got time to read the whole thread, but i am desperate for a Lemmings 1 level editor, in order to create more 2-player levels!

i hope this project might provide a solution. something that ripped the files, (use the imager slave from the WHDload version? if it uses disk images, then i know the JST install rips files!) then patched appropriately (like lemmings 2 editor) does seem a good solution to the copyright issues.

In that case you're in luck. I already have a working level editor, of sorts - it loads and saves levels fine, renders them pixel-perfectly, and lets you move items about... I just haven't got round to letting you add, delete or change properties of items yet. But it won't be too long. :-)

If you're desperate, however, there already exists a level editor for the DOS version, which conveniently uses the exact same levelfile format. You'll just need to be able to compress them with Lemmings' custom compression format before the Amiga version will load them. Luckily, I also have a compressor/decompressor, thanks to a good friend of mine who reverse-engineered the compression format from the Archimedes version (yet another version that shares most of the same datafiles :-) )

[Kinetic]

Thanks StingRay, you've fixed a hole in my knowledge there... I've been and read up on custom disk formats and it all makes a lot more sense now :-)

[StingRay]

You're welcome

[Hungry Horace]

Originally Posted by Kinetic

In that case you're in luck. I already have a working level editor, of sorts - it loads and saves levels fine, renders them pixel-perfectly, and lets you move items about... I just haven't got round to letting you add, delete or change properties of items yet. But it won't be too long. :-)

If you're desperate, however, there already exists a level editor for the DOS version, which conveniently uses the exact same levelfile format. You'll just need to be able to compress them with Lemmings' custom compression format before the Amiga version will load them. Luckily, I also have a compressor/decompressor, thanks to a good friend of mine who reverse-engineered the compression format from the Archimedes version (yet another version that shares most of the same datafiles :-) )

oh you are a legend Kinetic i will wait in the shadows for your full-works editor though will it allow for custom picture-based levels?

tbh, i want to avoid anything to do with the DOS version! and i wasnt aware of the two player mode being in that version anyway? (though i have barely looked at it!)

[Kinetic]

Originally Posted by Hungry Horace

oh you are a legend Kinetic i will wait in the shadows for your full-works editor though will it allow for custom picture-based levels?

tbh, i want to avoid anything to do with the DOS version! and i wasnt aware of the two player mode being in that version anyway? (though i have barely looked at it!)

The custom picture levels - "special" levels as the game calls them - are just basically ordinary levels that have no ground on them, just objects, with a parameter set in the levelfile telling the game to load an ILBM off the disk to use as a level image. I suppose I could stick the option in the editor to set special number, though TBH it's just as easily done in a hex editor ;-)

Regarding the DOS version, no I don't believe it has 2-player, but since it uses the same levelfile format as the Amiga, you should be able to make 2-player levels in the DOS editor without a problem.

[Hungry Horace]

Originally Posted by Kinetic

The custom picture levels - "special" levels as the game calls them - are just basically ordinary levels that have no ground on them, just objects, with a parameter set in the levelfile telling the game to load an ILBM off the disk to use as a level image. I suppose I could stick the option in the editor to set special number, though TBH it's just as easily done in a hex editor ;-)

add the option... you know you want to!

Regarding the DOS version, no I don't believe it has 2-player, but since it uses the same levelfile format as the Amiga, you should be able to make 2-player levels in the DOS editor without a problem.

i was thinking it might make it difficult to add the player 2 entrances / exits.


i'm looking forward to watching development of this. For me it's one of the most exciting new amiga projects i've seen in a long time. (i would say that, i was one of the 8 or whatever it was people who registered the Lemmings 2 editor!)

[Hungry Horace]

Originally Posted by Kinetic

In that case you're in luck. I already have a working level editor, of sorts - it loads and saves levels fine, renders them pixel-perfectly, and lets you move items about... I just haven't got round to letting you add, delete or change properties of items yet. But it won't be too long. :-)

I'd love to know what happened with this. I hope the project was not abandoned, as i'm sure i'm not the only one who would still like to see that Amiga Lemmings editor one day....

[Kinetic]

Woah, just noticed that after having gone searching for this thread for the benefit of a friend (and co-participant in this project!). Who'd have thought there'd be a reply after all this time?

So... no, it wasn't abandoned, it just went into hibernation for a while (a fairly lengthy while). But it's alive! The toolset is now essentially complete (including, yes, the level editor that you're so excited by :-) and the game itself is doing nicely too.

You can have a copy of the editor, if you don't mind the fact that it's linux-only at the moment and you'll need some way to get the files it saves into the game because it doesn't (and won't, and shouldn't) do that by itself. Though I can help you with that too :-) If you're still keen, drop me an email address (privately if you like) and we'll sort something out.