How a Nonstandard OS Led to Unix Standards

From 1988 through 1992, I worked as a system administrator for the Environmental Defense Fund in Washington, DC. As a nonprofit, it was too expensive for them to provide each employee with a PC, and Windows and PC networking were primitive back then, so their offices around the US used Wyse 50 terminals connected to a single computer in the copier room. When I arrived, that computer was a 68020-based Charles River Data Systems Universe 68, running their UNOS operating system.

CRDS Universe 68-35T closeup

Command-Line Utilities on UNOS

UNOS was sort of like Unix System V if you squinted, but it changed many of the details, so porting software to it ran into all kinds of incompatibilities. The command line utilities were maddeningly deficient and different from the 4.2 and 4.3BSD Unix I had used at college. Apparently CRDS was trying to make Unix more user-friendly or more like some other operating systems; their version of cp was named copy, dd was called debe (a pun on girls’ names?), etc. and the command line options were multiple characters long. Completely useless for running shell scripts written for Unix.

I started looking around for a way to replace them. I found the source code for half-finished versions of some utilities in the GNU source tree at MIT, where I had access as a volunteer thanks to my friendship with Mike Haertel, a former roommate who wrote GNU grep and diff. I finished them and wrote some more missing utilities, and thus started the GNU fileutils, textutils, and shellutils, which were later all rolled up into the coreutils. I also ported GNU Emacs to UNOS, including its tricky “undump” method of restoring a RAM image from a file for faster startup. EDF paid me to spend some of my time on this work, because they wanted more usable computer systems themselves.

So a good deal of GNU/Linux code was written to make up for the deficiencies of UNOS. After a few years, EDF switched to timeshared 486 computers running SCO Xenix, then SCO Unix, and we ran the GNU utilities on them, too, because they were better than the SCO versions. EDF finally went to networked Windows PCs for everyone, but they’re still using GNU/Linux for their web presence, at least, and using descendants of the utilities they funded.

Kermit on UNOS

Long before SSH, Kermit was a popular file transfer protocol which worked over both serial connections, like modems, and network connections, like TCP/IP. It was often paired with terminal emulators. It was implemented for nearly every type of computer made in the 1980s and 1990s, in many programming languages. Yes, it was named after the muppet, with permission.

EDF needed a good way to transfer files to and from its UNOS systems (besides UUCP), so I ported C-Kermit (the version for systems that use the C programming language) to UNOS. For that, I had to deal with many quirks in UNOS system calls.

Standards Because of UNOS

Mike O’Dell, Internet pioneer, related on an email list that the incompatibilities of UNOS led to the creation of the UNIFORUM association and the POSIX standards, so the US government wouldn’t have a sole source for Unix products that were interoperable. Thus, the obscure and quirky OS from CRDS contributed to creating both the official standards for Unix and what is now the most-used implementation of them.


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