dm@asgard.think.com (Dave Mankins) (10/27/89)
Firstly, saying ``cat > vmunix'' presupposes there being a unix already executing on the machine, or at least the dear old V6 shell that we know and love (which implemented ``goto'' by doing a seek on its standard input! and which had most other flow-of-control implemented as programs, not built-in commands). Secondly, at the time, the kernel was called ``unix'', not ``vmunix''. Third, the technique used was to to deposit the code using the switches on the front panel of the PDP-11. Which reminds me... Wizards can tell you the etymology of the name, ``dsw''. Also, a wizard understands the code ``explained'' by a comment in the V6 kernel which concluded, ``You are not expected to understand this.'' In addition to the Lions book, wizards probably also have a dog-eared copy of the old blue BSTJ special issue on UNIX (and eclectic wizards might have retained the companion volume on the Atlanta Fiber Optic installation). But this is ancient history. Hmm. A young wizard can tell you how ``['' in the Bourne shell works. Or, there is the old test: Someone who truly understands UNIX not only understands why ``rm *'' screws you, but understands why IT HAS TO BE THAT WAY. david mankins (dm@think.com)