My iBook G3 sends a scancode 107 which gets mapped to Delete. This is obviously not what you want when editing away in drawterm. To fix this issue dig deep into the X11 xkbd nightmare and change the line in /usr/X11R6/lib/X11/xkbd/symbols/apple that says
override key <BKSP> { [ BackSpace, Delete ] };
to
override key <DELE> { [ BackSpace, Delete ] };
Magic... now you have a working Backspace and Delete on shift+Backspace. Enjoy!