I recently transferred the code from windows visual fortran to PG fortran in unix. I am writing many output files. Logical unit number for each file is automatically generated. When I run the program, some files are getting written and some are not. When I debugged the code and forced the unit number as some other number like 2, 3, 4 and like that, the program seems to write. But when the numbers are like 800, 900 like that, the file is getting opened but no information is written to the file.
I could not find any information on logical unit number limitation.
Can any one provide some clue as why this is happening?