[TUHS] head/sed/tail (was The Unix shell: a 50-year view)

Nelson H. F. Beebe beebe at math.utah.edu
Fri Jul 16 02:54:35 AEST 2021


On the subject of tac (concatenate and print files in reverse), I can
report that the tool was written by my late friend Jay Lepreau in the
Department of Computer Science (now, School of Computing) at the
University of Utah.  The GNU coreutils distribution for src/tac.c
contains a copyright for 1988-2020.

I searched my TOPS-20 PDP-10 archives, and found no source code for
tac, but I did find an older TOPS-20 executable in Jay's personal
directory with a file date of 17-Mar-1987.  There isn't much else in
that directory, so I suspect that he just copied over a needed tool
from his Department of Computer Science TOPS-20 system to ours in the
College of Science.

----------------------------------------

P.S. Jay was the first to get Steve Johnson's Portable C Compiler,
pcc, to run on the 36-bit PDP-10, and once we had pcc, we began the
move from writing utilities in Pascal and PDP-10 assembly language to
doing them in C.  The oldest C file for pcc in our PDP-10 archives is
dated 17-Mar-1981, with other pcc files dated to mid-1983, and final
compiler executables dated 12-May-1986.  Four system header files are
dated as late as 4-Oct-1986, presumably patched after the compiler was
built.

Later, Kok Chen and Ken Harrenstien's kcc provided another C compiler
that added support for byte datatypes, where a byte could be anything
from 1 to 36 bits.  The oldest distribution of kcc in our archives is
labeled "Fifth formal distribution snapshot" and dated 20-Apr-1988.
My info-kcc mailing list archives date from the list beginning, with
an initial post from Ken dated 27-Jul-1986 announcing the availability
of kcc at sri-nic.arpa.
	
By mid-1987, we had a dozen Sun workstations and NFS fileserver; they
marked the beginning of our move to a Unix workstation environment,
away from large, expensive, and electricity-gulping PDP-10 and VAX
mainframes.

By the summer of 1991, those mainframes were retired.  I recall
speaking to a used-equipment vendor about our VAX 8600, which cost
about US$450K (discounted academic pricing) in 1986, and was told that
its value was depreciating about 20% per month.  Although many of us
missed TOPS-20 features, I don't think anyone was sad to say goodbye
to VMS.  We always felt that the VMS developers worked in isolation
from the PDP-10 folks, and thus learned nothing from them.

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