[TUHS] PDP-11, Unix, octal?

Warren Toomey wkt at tuhs.org
Tue Jan 17 06:15:43 AEST 2017


On Mon, Jan 16, 2017 at 11:10:37AM -0800, Steve Johnson wrote:
>    We would pore over the crash dumps (in hex, then a
>    new thing for us -- PDP-11 was all octal, all the time).

Something I've been meaning to ask for a while: why Unix and octal on the
PDP-11? Because of the DEC documentation?

I understand why other DEC architectures (e.g. PDP-7) were octal: 18b is
a multiple of 3. But PDP-11 is 16b, multiple of 4.

After all, Unix had its own assembler, so was there a need/reason to
use octal?

Cheers, Warren


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