* There was a version which was visible to software all the time.
* One version had a "invisibility" switch on the front in addition to the stop and reset buttons. When switched in one direction the multiface was invisible to software and in the other it was visible.''Is there a dump of the ROM from this version?''
* Last revision had an automatic "invisibility" switch internally controlled by the hardware itself. After reset the multiface was visible, but when the stop button was pressed and then control was returned to the running program it would be invisible and would remain invisible until the computer was reset.