Original version:
Thu Jan 7 12:15:05 2016
This directory contains source code and documentation for tputil, a once-heavily-used utility for reading and writing 9-track tapes on the DECsystem 20 under the TOPS-20 operating system running on PDP-10 KA, KI, and KL CPUs.
The PDP-10 processor supported about a dozen different operating systems, most with unique system calls. The tputil program depends heavily on TOPS-20 system calls, and the user-friendly TOPS-20 command processor that provides for inline help and completion. Despite the similar name, this code will not be use on the TOPS-10 operating system, which has a much more primitive command interface.
TOPS-20 is available now primarily on the fine KLH-10 and SIMH virtual machines, and thus, can be run on almost any modern platform. While those virtual machines do not have 9-track tape drives, they do provide simulated tape devices in software. In the absence of networking, and the venerable kermit program, (virtual) tape transfers may be the only easy way to move data to and from older systems.
Historical notes: Our last physical PDP-10 hardware, (Arpanet node UTAH-SCIENCE, later science.utah.edu, and still later, math.utah.edu) was retired on 31 October 1990. The then-Department of Computer Science (now School of Computing) at the University of Utah was node 4 of the original 5 nodes on the Arpanet that eventually grew to billions of nodes on today's Internet.
WARNING: Because the PDP-10 is a 36-bit architecture, and because .exe files are widely blocked for Internet access because of the sins of another operating system, this Web/FTP site does not offer an executable program for tputil. However, the program can be trivially built on TOPS-20 by commands in the .ctl file below.
The tputil program was developed at Stanford University, and radically extended at the University of Utah, at a time when software license statements were almost unheard of. In the spirit of academic publication, the maintainer of this Web page, who was a major contributor to, and long-time maintainer of, the software, declares that this software is freely usable and redistributable. The assembly-language source code contains an extensive revision history with author credits.
Those files are digitally signed in these separate digests: MD5SUM.asc, RIPEMD-160.asc, and SHA1SUM.asc,
P.S. There is a distantly-related program, read20, for reading TOPS-20 dumper filesystem backup tapes on other operating systems with 8-bit bytes.