scheme-debugger-mode
    
    scheme-debugger-mode is a compiled Lisp function in `xscheme.el'.
(scheme-debugger-mode)
Major mode for executing the Scheme debugger.
Like  scheme-mode  except that the evaluation commands
are disabled, and characters that would normally be self inserting are
sent to the Scheme process instead.  Typing ?  will show you which
characters perform useful functions.
Commands:
key             binding
---             -------
SPC .. ~	scheme-debugger-self-insert
C-c		Prefix Command
ESC		Prefix Command
DEL		backward-delete-char-untabify
C-c C-b		xscheme-send-breakpoint-interrupt
C-c C-c		xscheme-send-control-g-interrupt
C-c C-s		xscheme-select-process-buffer
C-c C-u		xscheme-send-control-u-interrupt
C-c C-x		xscheme-send-control-x-interrupt
C-M-q		indent-sexp