Yes, much better explanation, thanks.
So when you read the disk tracks directly, it's not really a file either, but of course those data that you read can be written into a file, and from there on it looks like you know what to do.
I'm not at all familiar with things like Amos or Blitz, but hopefully someone else can help more there.
Just be aware that when you read the raw data from the disk, you may often end up with chunks of data belonging to separate files, as they will often have been written to the disk interleaved with each other.
But if your aim is more or less to produce some "art" out of the data, that shouldn't be important to you, I guess.
Best regards,
Niels