Legacy system

As a complex technological system evolves, it is rarely able to free itself of its past. Hidden inside it are the vestiges of all its former states, a ghostwork of progress.

America’s original electric grid, built by Thomas Edison in Manhattan in 1882 and soon replicated in many other cities, was a direct current system. But the DC grid, doomed by its inefficiency, proved shortlived. When it became feasible to send power as alternating current, the new AC system quickly displaced the DC system, much to Edison’s dismay.

Yet Edison’s legacy lives on. Traces of the old DC system remain, in Manhattan and elsewhere. In fact, as Jennifer 8. Lee reports, it’s only today – 125 years after Edison constructed his original grid – that New York City’s electric utility, Con Edison, is finally shutting it down:

The last snip of Con Ed’s direct current system will take place at 10 East 40th Street, near the Mid-Manhattan Library. That building, like the thousands of other direct current users that have been transitioned over the last several years, now has a converter installed on the premises that can take alternating electricity from the Con Ed power grid and adapt it on premises. Until now, Con Edison had been converting alternating to direct current for the customers who needed it — old buildings on the Upper East Side and Upper West Side that used direct current for their elevators for example. The subway, which has its own converters, also provides direct current through its third rail, in large part because direct current electricity was the dominant system in New York City when the subway first developed out of the early trolley cars.

It’s no different with information technology. Whatever computers look like a century from now, they will, somewhere, still be running today’s code.

2 thoughts on “Legacy system

  1. Michael_ONeil

    That’s an interesting analogy! To add a little context from the software side – I met yesterday with a senior exec at “a large financial application vendor”. Part of our conversation was around whether it made sense for clients to adopt the best (operational) practices embedded in the software, or whether it made more sense to modify the software to accommodate the policies/workflow in use within the client’s business. The software vendor has a definite preference (they of course want customers to adopt both their software and their operating policies) – and the difficulties that clients experience when trying to upgrade modified code act as a bit of a “stick” to encourage clients to avoid code customization, and accept the operational definitions incorporated in the software.

    SOA is being positioned as a means of (at least partially) bridging this gap. There’s no doubt, though, that some of this vendor’s current clients will refuse to upgrade, and will become the systems-equivalent of DC power users later this century. What’s *really* bizarre, however, is the thought that at the end of the century, some of these clients will be using DC-analogous business practices/policies as a result of these implementations!

  2. Harald Felgner

    An eye-opener that puts into a 125-year historical context what we usually complain about on a much smaller time scale. “What, you mean I can still use DOS commands in Vista?”

    When you think about it, the signs of the past are everywhere. The DOS prompt in Vista, the Unix kernel of Leopard, the computer mouse (instead of pens and fingers), the QWERTY keyboard (instead of Dvorak or no keyboard at all), TV broadcast frequencies, and the COBOL and FORTRAN remnants all around (remember Y2K?).

    BTW, in case you know the story of Grace Hopper (involved in the development of the COBOL precursor FLOW-MATIC, running on UNIVAC machines) removing a moth from a Mark II computer relay in the 1940s as the first act of debugging. I learned today that the story is true indeed but it seems not to be the origin of the term bug which was used years before by …

    … Edison in the year 1889: In that year, the Pall Mall Gazette reported that “Mr. Edison…had been up the two previous nights discovering a ‘bug’ in his phonograph–an expression for solving a difficulty, and implying that some imaginary insect has secreted itself inside and is causing all the trouble.”

    [If you like historical newspaper articles, make sure to have a look at Tesla’s DC advantages from 1894 in addition to the article on Edison from 1882. Search the NYT Archive for ‘Tesla DC’.]

Comments are closed.