|Re: HP-15C, an interesting question|
Message #10 Posted by Tim Wessman on 20 Feb 2011, 10:49 p.m.,
in response to message #9 by Michael de Estrada
Yes, it would definitely need to be essentially rewritten, but the difference is that you are no longer guessing about the logic and algorithms so it is much easier to make something that is very similar. The 12cp was an attempt to "recreate" the 12c, but they essentially had to guess at how it worked. We all know how perfectly *that* worked out for the first few versions. . .
As an example (if I am remembering everything correctly), the 10bII had the math library from the 17bII and 48 converted into C (essentially a assembly->C converter program). This gave you C code, but really it was just assembly with tons of goto and so on like you'd use in assembly. As you can guess, that isn't very easy to edit/modify.
Thus later cyrille spent a long time remaking the math libraries in platform independent C by going back to the original assembly, using the documentation and source to redo it it, and that math library has now been used in several software versions (like the 12cp on iphone and the calcpad PC software), in the 20/30b and will be in future calculators/software.
The 15c source definitely wouldn't allow a simple recompile or anything, but it would make it possible to much more easily make a version of the 15c that could be easily expanded to allow more memory, operations, connectivity or whatever.
Edited: 20 Feb 2011, 10:50 p.m.