[vcf-midatlantic] computer superstitions

Jeffrey Jonas jeffrey.scott.jonas at gmail.com
Fri Oct 25 03:25:05 EDT 2019


> You need three sync's for it to work...
> sync
> sync
> sync
> halt

I'm unsure there was a halt or shutdown for Unix v6.
I think one just halted the CPU.

There's a good reason for three syncs.
The "sync" command only schedules/initiates the buffer/cache flush.
The disk writes took time, so typing it 3x on a teletype was a simple way
to delay the operator enough for the writes to complete before halting
the system.


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