-cbreak on System III

[cnrdean at ucbtopaz.CC.Berkeley.ARPA]

I am a programmer used to BSD Unix.  I am now trying to write something for 
System III.  Some old stuff no longer works:  


In an old BSD program, I have something that says:

	system("stty cbreak -echo nl");

This allows the user to execute commands with a single keystroke.  (It also
doesn't print the keystroke on the screen ...)  I never bothered to find out 
how to do this within 'C', rather than making a system call.

I can't find the equivalent in System III.  

Can you tell me either how to do this in 'C', or in System III?

Sam Scalise