On Tue, 2014-07-08 at 17:10 -0400, Robert Moskowitz wrote: > The read up on Grace Hopper and how she 'discovered' an unknown opcode > when a mispunch she glued in with nail polish. They used hand punchers > a lot on her programming team. Not entirely unknown because the opcode must have been known to the technicians or computer designers but not actually documented for the programmers. 40 used to be NOP (no op) on Honeywells H-200 series. -- Regards, Paul. England, EU. Centos, Exim, Apache, Libre Office. Linux is the future. Micro$oft is the past.