erlang:open_port_prim

[Bob Holmes]

Aloha,
First off:  THANKS to everyone for making this list educational and
interesting.

open_port eventually calls erlang:open_port_prim, which I don't find in
erlang.erl.  Where can I find it?

Bottom line is that I need to run a batch file which stuffs the keyboard,
then runs an old dos program.  This batch file approach works perfectly
from the dos prompt under windows, but hangs using os:cmd().  Any thoughts
on how to do this better would be greatly appreciated.

Thanks,
bob