- showpage -                              output and reset current page

- copypage -                              output current page

matrix width height proc banddevice -     install band buffer device

matrix width height proc framedevice -    install frame buffer device

 - nulldevice -                           install no-output device

proc renderbands -                        enumerate bands for output to device

* device devstatus free size              returns information about device

* device devmount bool                    "mounts " a cartridge device

* device devdismount -                    "dismounts " a cartridge device

* string cartstatus (type idfile type true)      returns status information
                 or (false)                      for a device or file