Comments on NOST 100-1.2

[Thierry Forveille]

John E. Davis writes:
 > On 8 Jul 1998 09:56:51 -0400, JENNINGS Don <Don.Jennings at obs.unige.ch>
 > wrote:
 > >The desire for support of unsigned integers has, I believe,
 > >been expressed before. Fortuantely, there is a way to store
 > >unsigned integers in the current FITS standard using the
 > >BZERO (for primary arrays and IMAGEs) and TZEROn (for
 > >BINTABLEs) keywords. See the CFITSIO Users manual for more
 > >details.
 > 
 > I think that this hack should be done away with in favor of real
 > support for unsigned values.  About the only reason I can see for not
 > adding such support is that older readers may have problems reading
 > the files with unsigned values.  But that's life--- software must
 > evolve.
 > 
I must say I have never seen any convincing argument for supporting
unsigned values. The present "hack" as you call it offers all the
functionalities for no cost, while adding unsigned as an additional
supported format would cost significant extra code to everybody for no
additional value. To me Occam's razor says it should stay out...

64 bit integers are a whole different story, as they bring real
improvements. The question for them is not whether, but when. We
will I think have to include them, but the present revision may or 
may not be timely.