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After working on some tools that parse the TR-DOS disk image format .TRD files for a while I just noticed that one of the game disk images I had downloaded "La Abadia Del Crimen", only has three files on it when I look at it in a hex editor, or with the tools I've been working on:

hex editor

You can see ABADIA..B, abadia..C, and ABADSAVEP. (The dots represent spaces, which are ignored, and the last letter is the type or file extension.)

But when I load the disk image into a virtual Beta drive on a Spectrum Emulator, Fuse on Windows in Pentagon 128K mode in my case, I see this when I enter the CAT command:

cat command output

And now there are four files! ABADIA <B>, abadia <C>, ABADSAVE<P>, and boot <B>.

In the disk image the rest of the directory area seems to be blank.

In the TR-DOS manuals it states that a Basic program file called "boot" is loaded and run, and indeed other disk images have the file no matter how I view it and I can see that they are regular Spectrum Basic files. I can find no mention of any kind of "virtual file" or "hidden file" or anything of that nature. I suppose it could be some kind of undocumented feature.

TR-DOS disk images are just flat dumps of the disk sectors and the disk layout is very simple. But it is a game so it could be protected with some trick known in the Russian/clone Speccy scene. Not only that, it's surely a crack since I don't think any western Speccy games were sold in Russian clone formats. And crackers liked to use tricks on their warez.

My attempts to load the file have been failing, but Fuse's support for the Russian clones doesn't seem as good as on Spectaculator, and my 30-day trial for it has ended. My other Speccy emulators don't support the machines it should work on.

So does anybody know what's going on here?

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I think possibly your emulator is fooling you. Per this FUSE feature request, leading to this patch in particular and this commit, FUSE synthesises a boot.b and adds it to the disk directory if you open a disk that does not otherwise have one.

So the reason that you can't locate the file within the disk image is that it isn't there. The emulator is inventing it to improve your user experience.

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  • Man my Google-fu must really be slipping. Thanks for this find! – hippietrail May 20 at 15:38

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