[TUHS] why does tar have the tape device hard coded into it and why is it mt1 instead of mt0

John Cowan cowan at mercury.ccil.org
Sun Dec 13 06:57:27 AEST 2015

Mary Ann Horton scripsit:

> But we never had dectapes and I think they did their own blocking.

Indeed.  A DECtape (aka microtape) was logically speaking a floppy disk
sliced into cylinders and then concatenated.  As a result it was possible
to rewrite any block without affecting later blocks, something not true
of conventional ("macro") tape.

My first system, a PDP-8/M, used a single DECtape drive as its system
"disk"; the second system, a PDP-8/A, used an 8-inch floppy.

John Cowan          http://www.ccil.org/~cowan        cowan at ccil.org
Don't be so humble.  You're not that great.
        --Golda Meir

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