Inevitable legal talk:

Some people warned me about possible problems with current owner of TOS copyright - who is it ? They don't know, what is sure is that it is not company Atari. First thing to know: I don't charge for part of improved TOS what is done by others. I charge for my work and lot of time spent on it. Dealing with Atari ST programming over 30 years. That's more than any of programmers of TOS spent, even if we count hours spent on it.
Atari company should be grateful that there is still people who dedicate their time and knowledge to prehistoric computer and it's OS. In fact, we make them free advertising - of course of name Atari. Lot of young people is not aware how important Atari was in late 70-es and 80-es.
As all TOS version images are available online for free, talking about copyright, piracy has no sense.
For the end of this short legal talk: something what happened with me and TOS 2.06 in 1992 . I seen adverts in diverse German computer magazines for TOS 2.06 - legal copies in EPROMs. Prices were in range 150-200 DEM . So, most of price was for intellectual work (well, I hope that sellers did not sell with huge profit) . That was too much for me, and I lived not in Germany, but in poor country, which was just became much more poor - the war started.
I even could not travel anymore to Germany without visa.  So, I called man in Belgrade, who advertized that sells TOS 2.06 in EPROMs. He asked 100 DEM (yes, in DEM, not in Yu dinars) . I said that it is too much, since EPROMs cost much less. (and before some silly talk 100 DEM in 1992 was more worth than 80 Euros now) . I offered him 20 DEM for images of it, what he could send me on floppy, or I could visit him and copy to floppy. He refused. And couple days later me and my Atari fellow went on phone BBS, and DL-ed TOS 2.06 practically free, maybe cost was about 1 DEM for 1 hour session. Yeah that was piracy. Or maybe not, considering low charge. Rather charity :-) Say now that such people destroyed Atari company - ahhh, they were already half past dead then.
The real question here is: should some owner of Atari ST computer pay full price for new TOS version when upgrades it ?
Is only way to do it (well, right word is: was ) ordering it from Atari or it's licensed sellers ?
How to legaly upgrade TOS in 2018 ?
I think that we all know the answers: it was practically almost impossible to do it legally even in years 1987-1994 . Especially for people in some country 'aside' . Today is of course totally impossible. And we know that it's common to charge less for OS upgrades than for people who buying it for the first time (unregistered user of OS) .