How to find out how many Input Data files DOC1Gen can have

This applies to all versions of DOC1 Generate

Number of Input Data files by Platform:

Windows -   1
Linux -     1
Unix -      1
AS400 -     1
Mainframe - 256

(DOC1Gen is seeing only one file, JCL using concatenated DD statements can call in a total of 256 files.)
 
The only HOST platform that you can call in more than one Input file is on the Mainframe where the files are controlled by JCL. 

On the Mainframe you can have up to 256 input files, all other platforms like Windows, Linux, Uniux, and AS400 it is just one Input Data file because you can have only 1 "DataInput=" parameter.
UPDATED:  August 18, 2017