[Web4lib] Conversion between ISBN-10 and ISBN-13

[Rick Mason]

Hi David,

According to the Wikipedia entry (i.e. don't start coding until you have 
confirmed the information elsewhere), the first three digits are a, EAN 
County Code for an imaginary country called "Bookland".  There are two 
codes for Bookland:  978 for existing ISBN codes (you can safely assume 
that the last 10 digits are an existing ISBN-10 and can be handled as 
such), and 979 for pure ISBN-13 codes.

It probably isn't a good idea to convert 979 codes to 10-digit ISBN 
systems because a) they use different check-digit calculations, and b) 
the final ten digits of an ISBN-13 can't be converted back into a valid 
ISBN-13 unless you somehow note that it needs the 979 appended.

Sites:
http://en.wikipedia.org/wiki/Isbn
http://en.wikipedia.org/wiki/Bookland_%28imaginary_place%29
http://www.gs1.org/

Hope this helps!  Good luck, if you decide to code it yourself!

Rick Mason

Patricia F Anderson wrote:
> There is already an online converter:
>
> <http://www.isbn.org/converterpub.asp>
>
> They offer the service to convert large stacks.
>
> "Need a large list of ISBNs converted? Enquire about obtaining your 
> converted list."
>
> To go from 13 to 10 is easy -- the isbn-10 is the last 10 digits of 
> thte isbn-13. Going the other direction, I haven't figured out yet 
> (not that I've tried hard).
>
>  -- Patricia Anderson, pfa at umich.edu
>
> On Sat, 30 Sep 2006, David Kane wrote:
>
>> Hi,
>>
>> Can anyone tell me what the conversion between ISBN-10 and ISBN-13 is,
>> please.  I need to write a little conversion program.  Anything in PHP,
>> for example.
>>
>> Thanks a lot.
>>
>> David Kane
>> Waterford Institute of Technology
>> http://library.wit.ie/
>> T: ++353.51302838
>> M: ++353.876693212