bash-3.2$ mit-scheme-c
MIT/GNU Scheme running under MacOSX
Type `^C' (control-C) followed by `H' to obtain information about interrupts.

Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
    1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
    2006, 2007, 2008 Massachusetts Institute of Technology
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Image saved on Sunday December 6, 2009 at 6:07:54 PM
  Release 7.7.90.+ || Microcode 15.1 || Runtime 15.7 || SF 4.41 || LIAR/C 4.118
  Edwin 3.116

1 ]=> (vector-ref (gc-space-status) 0)

;Value: 8