By Richard Sharpe

May 2022

‘Open’ was the word of the month 31 years ago in May 1991. The UK’s National Computing Centre, an autonomous non-profit organisation acting as the voice of the user, offered a testing service to verify that communications software complied with the Open Systems Interconnection (OSI) standard. (Software Markets 144/4 6.5.91) OSI had been first devised as a model for communication in 1978 backed by both the International Standards Organisation and the CCITT, the world body for telecommunications standards.

‘Open’ was code for ‘not-IBM’: not IBM’s proprietary operating systems, not IBM’s proprietary networking model, Systems Network Architecture (SNA). SNA was, for its time when launched in 1974, “a magnificent step forward to rationalise what was all sorts of weirdo communications things,” Maurice Perks told the Archive. Perks had worked in IBM from 1968, after becoming an IBM Fellow.

But by the early 1990s anything that was IBM proprietary was under fire. The word was ‘open’. Even IBM adopted OSI: in the same issue of Software Markets that May 1991 as the NCC offered its testing service, IBM announced an OSI-compliant communications package for its proprietary AS/400 mid-range business system.  Open could be and was being added to anything to make it seem accessible. As well as being code for ‘No-IBM’ in communications it was also code for the Unix operating system plus its associated programming language C. By May 1991 53% of the different classes of computers then used could run Unix: PCs 39%; Workstations 97%; Small business systems 69%; Medium business systems 43%; and large business systems 23%, according to Unix International. (Software Markets ibid page 9)

Bruce Bond, later at BT, was at the University of Colorado studying for his masters saw the dawn of this new open approach. He told AIT: a lab guy “took me down the hall and there was these two guys, one was named Ken Thompson and one was named Dennis Ritchie. And I walked in there and, what are you guys doing? And they said, oh, we’re in this big competition with IBM, IBM’s got this operating system that rules the world and that’s really the key to their success and we’re trying to develop something that we think could compete with that. And so we’ve been working on this new operating system. And I said, what’s an operating system? They said, well, it’s kind of a traffic cop thing. And I said, oh, okay. And they said, to do this we have to develop a new language to make it work. And they said, and we’re on the third version. The first version we called A and the second version we called B, and the third version we called C. We’re on the C version of this thing. And he said, this operating system is really different, because it treats everything the same, it’s kind of a peer-to-peer kind of operating system. So all the databases and the applications, they’re all the same thing. And so we’re trying to think of what we’re going to call it. And there was no whiteboards in those days, but they had a blackboard and they had a bunch of names, we need a sexy name to put on here. And in the middle they had this thing and it was circled, and it was called Unix.”

Bond worked programming microprocessors using C and Unix and realised that, with the growth of Moore’s law, such simple systems could soon challenge traditional telecommunications switching systems.”   Bond went on the evangelise for the use of Unix plus C as a platform for open systems and as an antidote to IBM’s proprietary approach. By 1991 package software developers were working hard to expand the number and variety of packages based on Unix and C: the same issue of Software Markets that May reported that in Germany the total application packages running on Unix and C was over 3,000, rising at 21% a year.

A lot of these applications, especially in the small and medium business market, ran on Digital Equipment PDP and Vax minicomputers. This challenged IBM’s hold on the business market using the mini architecture, devised for technical and scientific computing, in the business market. Geoff Shingles CBE from Digital UK and Europe explained to the Archives: “I had come from a scientific and engineering background. So, we were less experienced in the actual applications which people were now starting to try to use our machines for. But the thing that I feel we offered was, was high quality, reliably engineered, good products, maybe not having all the applications, apps I guess now they’re called, that were needed, but, people had felt grasped warmly by the throat by some of the larger manufacturers, IBM, maybe NCR and others, they were, they were restricted by them.”

But, and there is almost always a but in technology, Unix was not just Unix. There was the Unix of Unix International, the AT&T company which promoted the operating system and language first born within AT&T. Then there were the versions from different vendors, Sinix from Siemens Nixdorf Information Systems, and AIX from IBM; and there was Linux and GNU in the open software sphere. And more.

Mandy Chessell CBE told the Archives of her fight for open systems within IBM: “When we were so dominant, we always had, products competing – two of every type so that there was competition because we didn’t have external competition. And that was one of the things that threw the company because we were set up to compete internally. And then when the external competitors came along, of course, we weren’t watching ‘cause we were used to competing internally and that was a big cultural change. We had our own networking system called SNA and we then moved to TCP/IP and all the open standards for things. And for a long time, we supported both but now, of course, that is the industry standards…One of my very early jobs, I switched to open standards and I’d been called a traitor…but it’s always a move to open—open and the open-source movement underneath it, which is creating those sort of de facto standard implementations of technology. I mean the internet is almost all open source now, isn’t it, and think how successful that’s been.”

Software Markets Highdon Publishing, London.