Old Fortran Code - Need to Figure Out What This Means 3

[jamez05]

Have some old Fortran (believe its 77) that I'm trying to
convert. Its working, except the old skips the lines of code that have a "D" in front of it, like a comment. I'm not sure why it does this. Does anyone know if "D" is some sort of directive that tells the compiler not to compile or does anyone have any insight. Below is some code. Notice the "D" on the far left:

  X= X+SSEMES('RN{0}(R)R '    ,'Ring -N<:' ,0.007 , 5,1,L)
D X= X+SSEMES('RN{/}=R ' ,'-N=:',0.014 ,44,1,L) ! (cf. #4)
D X= X+SSEMES('RN{0}=R ' ,'RingN=:',007 ,45,1,L) ! (cf. #5)
11111

 

[jamez05]

Figured it out, the D is the Debug processing directive. It only runs the lines prefixed with "D" when in debug mode.

 

[xwb]

Any non numeric character in column 1 forces the line to be a comment. D must be a special feature of your compiler.

 

[gummibaer]

Yes, this is a feature of a special compiler. I do not know if this was the compiler running on a thing called DEC PDP 11 or an old Lahey F77 compiler. I think its the latter but I am not so sure.

Norbert

 

[xwb]

That's going back a bit. DEC was taken over by Compaq which was then taken over by HP.

 

[zeitghost]

A thing called a PDP11

Oh, how the mighty are fallen...

 

[jamez05]

Thanks for the history, interesting to track this code's origins (barely any documentation, just piecing it together).