One final comment. You may come across things I wrote
years ago with
 comments like 'This is not Public Domain, it is released for the benefit
 of PERQ fanantics...'. It is _not_ leagally public domain, I will not
 totally give up the copyright (for good reasons)., But I will take a very
 wide definiton of 'PERQ fanatic' or whatever. If it helps you write a
 PERQ emulator, or archive some PERQ disks, or.. then you're a
 PREQ-fanatic. 
    You're completely right. That is not because you make it avaiable to
people, it has to be "public domain". It was made by you, and the copyright
is yours.