I created a quite simple but large EXCEL-File with EXCEL2000 with a size of 
about 35MB.  This file uses 4 XBAT-Blocks.
When building the BAT-array from these XBAT-blocks I encountered a problem ( 
which arose the moment more then 1 XBAT-Blocks was needed ).
It seems as if not all 128 integers in the block were holding indices of BAT-
blocks but only the first 127 of them.  The last integer ( at offset +1FC ) 
pointed to the next XBAT-Block.   The same was true for the other XBAT-blocks 
as well.
Thus the last integers of all XBAT-blocks formed a chain just like the one 
found in the BAT-Array with the last XBAT-Block having -2 as end-indicator 
while the other integers of all these blocks formed the extension of the BAT-
Array.

Can anyone confirm the behavior mentionend above or is this an error on my 
side?

If the previous were true, then the XBAT-Blocks would not necessarily have to 
be located in sequence as described in the documentation here

http://jakarta.apache.org/poi/poifs/fileformat.html

and the BAT-Array is only extended by 127 of the 128 integers of each XBAT-
block.


If needed I can submit a zipped version of the file indicated ( still 5MB 
size ) but I guess any file large enough created by EXCEL will do.

live long and prosper
Stefan Schmöcker