From mboxrd@z Thu Jan  1 00:00:00 1970
From: cowan@mercury.ccil.org (John Cowan)
Date: Sat, 12 Dec 2015 15:57:27 -0500
Subject: [TUHS] why does tar have the tape device hard coded into it and
 why is it mt1 instead of mt0
In-Reply-To: <566C6D60.40205@mhorton.net>
References: <201512120209.tBC2930f007838@coolidge.cs.Dartmouth.EDU>
 <566C6D60.40205@mhorton.net>
Message-ID: <20151212205727.GE15143@mercury.ccil.org>

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