Hi Eddie,
First of all, it is very saddening to hear that Dr. Thomas Metcalfe died
in an accident. I also own a Nav48 and it is truly a magnificient piece
of software. I am very interested in your porting work to the HP 50g,
because I own only one card and never could find a second one. I am very
hesitant to take this darling to sea, for fear of losing or damaging it.
Now for the legal part, I am familiar only with Swiss law, but I presume
the US law to function along the main lines.
1) The author has the exclusive right to say if, when and how his work
may be used.
2) The author has the exclusive right to say:
- if, when and how the work may be changed.
- if, when and how the work may be used for the creation of the work of
second hand.
These rights are transferrable and inheritable. The copyright (in Swiss
law) extinguishes only seventy years after the death of the original author.
It is not immediately obvious who own the rights now. The author might
have transferred the copyright to Sparcom, who in turn might have
transferred the rights to someone else upon quitting business, but this
is indeed difficult to know. One possible source of information could be
the authors of other Sparcom cards.
If not, the author or his heirs still own the full copyrights.
In any case I think you will have to ask Dr. Metcalfe's family in due
time for explicit consent to disseminate his work in original or changed
form.
I cannot say for sure if under US law it is legal to distribute the
tools alone to change the Nav48 to be used on the HP 50g - under Swiss
law it probaly would be, but e.g. in Germany this is not allowed. But as
discussed above, the process of changing the sofware would constitute an
infraction, strictly speaking.
I'm sorry to say, but these copyright issues are not trivial. You are
perfectly right to be careful. I can only recommend to make sure
everything is in order before you disseminate anything, even the tools.
If I can be of further help please let me know. I own a few other
Sparcom cards, it would be interesting in general to find out what
happened to the copyrights and if these works could be transferred to
different platforms.
Thank you very much and best regards
Chris
Post by e***@brainaid.dePost by Joe HornPost by e***@brainaid.deDoes anyone know the copyright state and/or who to contact for the old
Sparcom HP48GX cards?
The copyright is stated in two places: in the manual, and in the card
itself. The Sparcom copyrights are still defendable by the respective
*authors* of the software. Contact the authors for permission to copy
their intellectual property.
Post by e***@brainaid.deI have successfully ported the Sparcom Nav48: Celestial Navigation
library to my HP50g, and I am wondering whether I may make this work
public or whom to contact to ask.
If the authors are not mentioned in the manual, you'll have to do some
hunting to find them. Until you do, do NOT consider it to be in the
public domain, unless you know for certain that the authors placed the
software in the public domain.
Disclaimer: Opinions are free. Legal advice is expensive. The above
was free.
Post by e***@brainaid.deOn a sidenote, does anyone know the size limit of a library in Flash,
i.e. Port 2, of the HP50g?
Port 2 is a collection of 128K banks. Libraries and backup objects
cannot span banks. Therefore no single object in port 2 can be larger
than 128K. Ditto for port 1. Only ports 0 and 3 (and main RAM) can
handle objects larger than 128K.
Hope that helps!
-Joe-
Thank you for the info. The maximum size of a library in Flash is
probably
128K - (256 + 6), correct? The 256 + 6 come from the offset of and the
marker
in each Flash bank.
About the copyright, I want to respect this, therefore I ask. The
problem with the
Nav48 Library is that sadly the author Dr. Thomas Metcalf just died in
a skiing
accident a few days ago. I truely mean sadly, as I respect him as a
fellow seaman
and navigator. His software is so good, I could not have done anything
near as usable.
What I probably can do is publish a difference set together with a
tool to convert
the software so those that own the Sparcom card can use the software
on their
1. Read a library or other HP object into memory, decoding the
structure and
sysRPL names from an entry database for the input calculator model.
2. Dump the object using the entry database for the output calculator
model.
Works quite well, except some issues with Symbolics/CAS, display size,
keyboard
1a. Write out the object in rplcomp or so ASCII so it is human
readable.
1b. Read a "patch" instruction File to apply to the object. This patch
would be
a context diff between the original ASCII representation and the
modified one.
I have 1. 1a. and 2. done, and fiddled with the stuff by hand for the
Nav48 library.
With 1b. I could supply a diff against the original software which
would not contain
code of the original. This should be allowed, or do I miss something
here?
Eddie