Unix in East Germany (GDR)

The following article appeared (in German) on the German UUG net andSubNet. It tells a short history of Unix in the German Democratic Republic.The original author (Guenther Fischer) can be reached atg...@tu-k-ddr.cs.tu-berlin.de.Translation and redistribution is with the author's permission.The original can be had by emailing me (p...@iis.ethz.ch).Peter Lambuucp: uunet!mcsun!ethz!prl eunet: p...@iis.ethz.ch Tel: +411 256 5241Integrated Systems LaboratoryETH-Zentrum, 8092 Zurich UNIX at the TUK/IF Attempt at a private history.Technical University Karl-Marx-Stadt, Computer Science DepartmentGuenther Fischer und Matthias ClauszTranslation Peter Lamb, ETH Zurich, with the kind permission of the authors.Getting started1982 - our department had none of its own students (a department withoutstudents is like a dried-out tree) - we were more a service departmentfor the whole school (teaching and technical computing services).Our computing base was 2 ESER I machines (alias IBM 360). We hadfinally made the jump from DOS to OS, and then with some pressureswitched over to TSO - our slogan then was `TSO keeps everyonehappy' (TSO macht alle froh) [ perhaps the abuse of dead whalesis popular in the GDR - pl :-) :-) ]. We were also just aboutready to move away from Assembler programming.The lucky break.One day a magtape, which our IBM-clone could make nothing of, fell intoour laps. After analysing it with Hex-Dump it wasn't so hard to see theASCII codes and the 512-byte blocking. Even if you don't know whatit is, it's not so hard to read and print out a tar-format tape.What we then saw on paper (our printer had only capitals and therestricted special characters from IBM stone age), was cryptic enough.The comments and the README's gave away the secret.It was a [compiler for a - pl ] programming language and the nameUNIX appeared occasionally. Literature research quickly broughtlight onto the matter.

We even found an unnoticed book in the department;Kernigan&Ritchie's `The C Programming Language'.We were immediately enthusiastic about the idea that an operatingsystem could be written in a high-level language and could run on differentmachines.Literature searches, a draft translation of the `C' book and an implementationof the `C' preprocessor cpp in our System-Pascal (our first attempt at analternative to Assembler) rapidly made us known in the Unix-scene in the GDR(in the land of the blind, the one-eyed man is king).In this way we came into contact with other Unix efforts in the GDR: theFroelich brothers (ZKI and LfA Berlin), our collegues in ZfT KEAW Berlin andthe TH Ilmeneau, as well as the small team at Robotron Dresden.How to knit a C compiler.Encouraged by the success of the cpp effort (translation into a languagesimilar to `C'), we continued on to the port of the compiler itself.Since we had no machine with a `C' complier, we chose the same method:translation by hand into another language. In a finite time (about3 months), we had a `C' compiler which produced PDP/11 assembler. The nextstage for us, relatively computer-ignorant, was more complicated. We had toconvince the code generator to produce IBM 360-Assembler, and the codeshould also be reasonably good. After the first few attempts, we got thefirst hello worldon the screen fairly quickly. After about 4 months we succeeded in compilingthe `C' compiler itself. Of course it was initially PDP/11 code that came out,but from then on, we were able to think in `C'. The alterations to the codegenerator had to be ported back into the original compiler.Unix - the first stageWe built up our relationship with LfA, since their work on PSUwas closest to what we wanted. PSU was planned as a subsystem underOS. PSU was similar to Unix, but was restricted -- in particularmultiprocessing was simulated sequentially. The first GDR-Unix wasa batch system, and was implemented in assembler.

As TSO `sharks', we missed the interactive capabilities, and we assistedthe port of PSU to TSO with advice and action. As soon as PSU ran,we ported our compiler to this environment -- the first version ran under OS.We also worked in close association with LfA on the compiler.The bulk of Unix tools could then be ported to PSU. Wump (`hunt the wumpus')enjoyed great popularity -- in the graphics age nobody remembers this program.Other Uni's and Colleges assisted with the ports and helped find compilerbugs. But we had a real cuckoo's egg in the nest (or rather LfA had put onethere), since PSU used EBCDIC.Some ports (eg. nroff) were true works of art.But our efforts began to bear fruit: - the students and staff could work with the same tools both in batch and interactively, - OS and TSO could no longer be seen, - we could start to educate ourselves for the future. Unix - stage 2Parallel to our PSU activities, we ran Unix V7 part-time on a `foreign'[non-360 - pl] machine (PDP 11/20) to get some `real' Unix experience.Later we ran two such machines in our department, which could then beeasily incorporated in our education and reseatch efforts.Unix - stage 3We moved to a new situation when our two 360's were exchanged for 370's.We wanted to put real Unix on the new machines. Development efforts,much enthusiasm and a few happy coincidences put us in the position of beingable to port Unix such that we had full source, that supported all ourperipherals, and that could run `standalone' (without VM), and for whichwe now had complete German documentation. Th this phase we were activelyassisted by TH Leipzig and FSU Jena.The associated installation of about 30 Unix terminals brought us a good pieceforwards in education and research. However our so-called `mainframe' with0.5 MIPS is often overloaded and sometimes requires patience.From this basis came numerous developments: - a job scheduler to permit overnight scheduling - interactive use was insufficient to meet all the computing needs for the students' prac.

work. - a number of compilers: Pascal, Modula 2, Lisp, C, C++, - numerous technical tools.In the meantime - 8-bit microsThese systems ran CP/M are only mentioned because they were thebasis for education with Turbo Pascal, database and textprocessing systemsand serve still as stable workhorses.8 + 8 = 16 == P8000A significant improvement in our computing misery was brought bythe use of P8000 systems. These machines, based on the Z8000 ranthe Unix system WEGA.Unix == Unix ? great : not-so-greatAt last it was clear: it was advantageous to run Unix on all our computers(except for the 8-bit machines), but Unix'es can be quite different from eachother. VMX (our 370 system) was approximately Version 7, and WEGA was supposedto be System III compatible. As passionate collectors of Unix literature,we naturally followed all the activities of from /usr/group, SVID and X/OPENup to POSIX.GDR-UUG (EAG)"GUUG and EAG: why not unity from below?"All GDR Unix developers saw a great need for a uniform documentationof all the varieties of Unix systems. Two years ago we started to writedocumentation for system calls and library functions, which were basedupon X/OPEN and SVID; roughly equivalent to System V Release 2. The commanddocumentation (man1) followed. All systems, where possible, should conform tothis standardised interface. Where this was not possible, at leastthe differences should be documented.This has been pushed quite far for two systems (VMX and MUTOS 1835). Ourdocumentation was made available to others through the EAG, to serveas an example for further systems.The Flop.MUTOS 1835 was a UNIX port which we did under contract for an AT-compatiblefrom Robotron. Since this machine was never produced, the whole thingmust be seen as a flop.Unix -- here and now.We see our efforts with X and ET++ on the AT/286 as trainingfor better (hardware-) times.

We should have been working on thedevelopment of a 386 for the past year, but so far it has not beenpossible for us to turn up even one such machine.In the meantime, another K1840 (VAX/11-780-alias) has been installed,running its now-standard operating system Unix-OS MUTOS 1800.At the moment we are working on bringing VMX up to System V Release 3.This work is largely being undertaken as student projects.... and Tomorrow?We have been following the GNU project with great interest, the current workof X/OPEN and OSF, particularly now that AIX has been replaced by Mach.We are told that OSF is interested in University partners!?And here are we by our current problem: What are our directions forour research? Formerly, we were behind double walls -- one we built ourselvesand the second by the West (eg. COCOM) -- but even this is crumbling.Our catching-up of the last years came from a sense of emergency, and welearnt our trade through it. Now we need security for our future researchwhich will give us the freedom to purchase new hard- and software, participatein international conferences, connect to networks andupdate our literature.Whether this comes through cooperative projects with other institutions,through industrial research or however, is almos irrelevant to us --we want, as far as possible, to determine our own future and not wait untilit comes to us from `above'.This last paragraph may be taken politcally.Author: Guenther Fischer (g...@tu-k-ddr.cs.tu-berlin.de)Glossary of abbreviations:TH - Technische Hochschule (Technical College)EAG - Entwickler- und Anwendergemeinschaft / GDR-UUG : GDR-UUG; now also GUUG/eastZKI - Zentralinstitut fuer Kybernetik und Informatik : Institute for Cybernetics and InformaticsLfA - Leitzentrum fuer Anwendungforschung : Software CompanyZfT KEAW - Zentrum fuer Technik im Kombinat fuer Elektro-Apparate-Werke : Technical Centre, Electrical Equipment Combine - R&D Centre for (amongst other things) electronic control.

FSU - Friedrich Schiller Universitaet-- Peter Lambuucp: uunet!mcsun!ethz!prl eunet: p...@iis.ethz.ch Tel: +411 256 5241Integrated Systems LaboratoryETH-Zentrum, 8092 Zurich