where and how do i set up the unix machine so that back space works ?
I'm guessing thet your backspace key produces either a ^H or a ^?. One way to fix this is to type:
stty erase <backspace>
(i.e. hit your backspace key for the last charecter on the line)
You can put this in your .profile or .cshrc as appropriate to run everytime you login.
You have a couple of choices. Try reading the manpages for:
stty erase <backspace_key>