APPLICATION NOTE #122
 SORT KEY IN XYWRITE III PLUS
 Rev. 01


 The SK (Sort Key) setting has some capabilities that are not 
documented in the XyWrite III Plus Reference Guide. They are 
undocumented because we plan to revise the function significantly in 
a future release; you should therefore be conservative in your 
application of the SK settings described here.


 FORMAT OF THE SK SETTING
 The SORT command allows you to rearrange the entries in a file or in 
a defined block into alphabetical order. By default, the first 80 
characters of each entry are used in the sort; numbers are sorted in 
decimal order; and duplicate entries are preserved. You can change 
one or all of these defaults by using the DEFAULT command to change 
the SK (Sort Key).

 The SK setting has the following form:

  default sk=n1,n2,n3

 where n1 is a combination of one or more of the following numbers:

  0  Sorts numerical entries in ASCII order (01, 10, 2, 3).

  1  Sorts numerical entries in decimal order (01, 2, 3, 10).

  2  Sorts entries in reverse order (Z to A and 9 to 0).

  4  Deletes duplicate entries.

  8  When set, means that n3 defines the number of tabs to skip
     rather than the number of characters.

 The default value for n1 is 1. To change n1, use one of the numbers 
listed above or add two or more of the numbers to create the sorting 
effect you want. For example,  to sort numerical entries in decimal 
order and delete duplicate entries, set n1 to 5 (1+4); to sort 
numerical entries in decimal order, delete duplicate entries, and 
reverse the order of all entries, set n1 to 7 (1+4+2); to sort 
numerical entries in decimal order and skip tabs rather than 
characters, set n1 to 9 (1+8).

 The second value of the Sort Key (n2) defines the number of 
characters that XyWrite uses when sorting a list. The default size is 
80, which means that the first 80 characters of each entry are 
sorted. If you have a very large file, you can reduce the amount of 
memory required to sort it by defining a smaller number of 
characters. Similarly, if you are creating a very large index, it is 
a good idea to define a smaller number of characters to be used for 
sorting.  There is a limit to the size of the index file that XyWrite 
allows you to create. If you specify a smaller sort size, then you 
can include more entries in your index.

 The third value of the Sort Key (n3) defines the number of characters 
or tab columns that should be skipped before the sort starts. (The 
default is 0.) Suppose you have a list of entries that start with a 
5-digit part number followed by a description. For example:

  41233  Tennis racquet
  41234  Baseball bat
  41235  Football helmet

 If you want to sort this list by description rather than number, 
specify the number 6 as the third value of the Sort Key. The Sort 
program will skip over the 5-digit number and the tab, and start its 
evaluation with the 7th character. Alternatively, you could tell 
XyWrite to skip over the first tab column and sort the list using the 
first character of column 2. To do this, add 8 to the current value 
of n1, and then set n3 equal to the number of tab columns you want to 
skip (1 in this example).


 MORE INFORMATION
 For information on how to use the SORT command and how to set up a 
Sort Table, refer to the XyWrite III Plus Reference Guide.