Building DIR/ECT II

VAX 11-785

In 1975, when I was 37, I got my first and only job at Bell Labs which was not research. Bell Labs had written, a long time before, an elaborate software system, named DIR/ECT, used in printing white pages phone books. This sounds like a simple job, but the rules for how listings are arranged, alphabetized, and displayed in the white pages were arcane, dating back to the turn of the century. This software was obsolete, using batch processing with data on magnetic tapes. It was hard to use and error prone. I was asked to look at it to see what could be done.

I worked with Ron, the head of the department maintaining the DIR/ECT system. We looked at the system and decided that it was not practical to improve it; to bring it into the modern on-line age. We decided that a new system should be built. Officially named “DIR/ECT II,” we called it “the upgrade” to emphasize that it would be fully compatible with the old system. The work of maintaining the old system, and of building a new one, was funded by the “operating companies,” the telephone companies that were part of AT&T. So Ron and I had to convince the operating companies that a new system was needed, and to fund it. This was not difficult, since the old system was so difficult to use. We estimated that the job would take three years.

I formed a new department, which ended up with 50 people under seven supervisors, to build the new system while next door Ron’s department of about 30 people maintained the old system.

DIR/ECT II (the “upgrade”), my first and only Bell Labs job outside of research, was by far my largest department, and my least successful job. Since it was being paid for by the operating companies (the AT&T telephone companies) I had the job of presenting our status in a twice-yearly meeting of the companies, to convince them to continue funding the project. At first these meetings were easy, but as we missed our deadlines they became quite difficult. Meanwhile, back at the ranch, we realized that the job was much more difficult than we had thought, and much more expensive in computer time. It took us almost five years to complete DIR/ECT II, not the expected three.

I had decided early on that we would build the system on UNIX using a DEC (Digital Equipment Corp.) minicomputer. DIR/ECT II was the first AT&T product built on UNIX, and perhaps the first on a minicomputer. The decision to use UNIX was controversial, largely because UNIX only ran on minicomputers. It turned out to be an unwise decision. The computational demands of the system were much higher than we expected. At that time DEC dominated the minicomputer market. I remember us using a DEC VAX machine, but Wikipedia tells me that the VAX machine was introduced in 1977, so perhaps we started with a DEC PDP-11. In any case, a couple of years into the project we realized that we needed a faster machine. Fortunately DEC was about to introduce a new machine, and the salesman assured me it would be much faster. Previous releases of new machines by DEC had each doubled the speed of its predecessor, but this time the new machine, when it became available, was not much faster. So we spent quite a bit of time trying to make our system more efficient. When we finally went to trial, in Florida, performance was marginal.

Meanwhile Ron, who had the old department, had a difficult job. How was he going to motivate his people to work on the dinosaur while next door people were working on a sexy new system? Ron decided to challenge his team to improve the old system so drastically that by the time my new system was available the operating companies would not need it. Neither Ron nor I thought this was possible. The old system was just too cumbersome. But we agreed that the challenge would be good for his team. Ron invented the slogan “Obviate the Upgrade,” and threw down the challenge. To our surprise, by the time my team finished the upgrade, the old system had been transformed into a modern, on-line system. And, indeed, after the new system had successfully passed its trial period, none of the operating companies wanted it and it was abandoned. Ron and his team had done a terrific job.

Moral: competition can lead people to accomplish remarkable things.

– Rudd Canaday (
    – Start of blog: My adventures in software

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