namelist.txt

Digital DATCOM Source Code and Examples

  SOME GENERAL COMMENTS ON NAMELIST
  (USED IN Datcom, WingBody, NACA4, and NACA6)

Some of the programs in this collection use the namelist formatting
scheme for input. This feature has only been part of standard Fortran 
for a few years and it may be understandable that there are
differences in various manufacturers implementation. 
There are two places where the differences occur: the coding of the 
program and the formatting of the input data.

The new standard for Fortran indicates that the form of an input
statement using namelist is:

     READ(UNIT=k, NML=abc)   where k is an integer and abc is a 
namelist name appearing in a statement of the form
     NAMELIST /abc/ ......

The Lahey compilers and the Microsoft PowerStation compiler
conform to this notation, but if you are using Watcom F77, v 9.5,
then you must change to
     READ(UNIT=k, FMT=abc)
if you decide to modify the program and recompile it.

The input data for this statement should be written as:

 &abc   ...data items
   .more data items
   /
where the forward slash indicates the end of the data.
Earlier implementations required the & to be in column 2, but
this has been relaxed. Previous versions of Fortran used an
ampersand (&) as the terminating character instead of a slash.
However, all the compilers still accept the ampersand character
as the end of data indicator. Some day, we will all be using /,
but for now, I have supplied the test cases with & so as to be usable
with the .exe files which were made with Lahey Fortran F77L.

For the millenium, I will update them to proper Fortran 90 syntax.

The DATCOM cases use $ instead of & as the beginning and ending namelist
characters. If you look at the code carefully, you will see that the
native namelist of Fortran is not being used, but that an entire
namelist emulator has been written for Datcom. This was probably a
smart move back in the 60s and 70s before namelist was standardized.