JOSheaIV 119 C# Addict

Hello everyone, I am back with yet more Fortran problems it seems. So I have spent some time working on trying to understand the C code that was produced from my f2c conversion of some Fortran 77 code. Well to understand it better I have been trying to use f2c to create a C executable.

Unfortantly there are some issues with the code. One was what I believe to be a need for an external library (something that might be hard to find). I'm pretty sure I fixed that issue, however I can't really test it because it isn't the only error. When I try using the following command to create the executable:

f77 -o advf4 advf4.f

I produce the following output

advf4.f:
MAIN:
Warning on line 660 of advf4.f: local variable default never used
speak:
getin:
yes:
shift:
advf4.o: In function 'MAIN__':
advf4.c:(.text+0xc1c): undefined reference to 'ran_'
advf4.c:(.text+0xf19): undefined reference to 'ran_'
advf4.c:(.text+0x1234): undefined reference to 'ran_'
advf4.c:(.text+0x1639): undefined reference to 'ran_'
advf4.c:(.text+0x18bd): undefined reference to 'ran_'
advf4.o:advf4.c:(.text+0x1907): more undefined references to 'ran_' follow
collect2: ld returned 1 exit status

I have no clue what's causing the error because to me "ran_" looks just fine. I have uploaded the code to pastepin, here's the link http://pastebin.com/1aP0iE6k

I really can't figure out what's causing this error, as it seems "ran_" should be declared fine, so I am left stumped here and could use some help.