“It works - don’t touch it”: Old code and computers that are still functioning

    In the modern world, in which a two-year-old smartphone seems to be an outdated technology, the fact that many businesses and state-owned companies use programs that have not been updated for decades for many years remains surprising.

    According to a study conducted by US government, the Secret Service still uses a computer system created in the 80s of the last century. Similar "old" solutions are also in service with many countries of the world and are used to control ballistic systems, submarine systems and aircraft.

    Therefore, today we would like to tell some stories about computers and programs forgotten by time, but not forgotten by stubborn people. / photo Judit Klein CC



    The Last of the Mohicans


    Sparkler Filters in Conro, Texas, has been on the market for a very long time and offers filtering devices. And if you place an order for the nutsche filter with them, they will enter the transaction data into a computer that has been operating since 1948.

    This computer is an IBM 402 . Of course, this is not exactly a computer, in the traditional sense, but an automatic electromechanical calculator that can be programmed to print the results depending on the values ​​entered from 80-column punch cards.

    In the middle of the last century, such devices were often used by companies for counting. The machine could take a long list of numbers, add them up, and print a detailed report. In a way, this is a multi-kilogram Excel spreadsheet processor. It is for these purposes that Sparkler Filters uses 402, which is the last fully functioning IBM 402 on the planet.

    The machine prints reports on wide paper with leading holes, and Carl Kracklauer, whose father founded Sparkler Filters in 1927, enters data on punch cards. The company does not switch to “modern” equipment, since 402 is a familiar solution. The staff knows how to use the system, and 60 years of company credentials are formatted to work with the device.

    / photo by Simon Claessen CC

    Sparkler Filters also has dozens of programs for the IBM 402 in the format of patch panels . To write a program in the 40s, it was necessary to redistribute hundreds of wires to different panel sockets. In this case, the panels can be replaced as if they were removable disks with software.

    The IBM 402 at Sparkler Filters is such a significant computer relic that the Museum of Computer History sent a delegation to the company to convince employees to upgrade to more modern systems and transfer 402 to the museum. Someday it will be a worthy place for the rest of the "old man", but so far the Texas company has decided to postpone the retirement of this computer technology dinosaur.

    MOCAS system


    But not only computing systems have been living since the middle of the last century. There are centenarians among computer programs. In 1958, the US Department of Defense launched the MOCAS computerized contract management system, which was supposed to monitor existing contracts and payments. And she watches, 59 years later.

    MOCAS is written in COBOL, a language that was not officially approved at the time of writing. MOCAS originally worked on punch cards, but over the past decades, the interface has been redesigned. At first it became terminal. Then he got a web shell.

    Web interfaces often hide the age of older systems. The Ministry of Defense has provided MOCAS with a new interface to keep it operational in modern realities. In the current version, the system can be integrated with other software packages, for example, the user has the ability to attach Microsoft Word documents to records.

    The Pentagon is afraid to change this system to a more modern one, since it works with $ 1.3 trillion in bonds and 340 thousand contracts. It runs on the IBM mainframe, which is capable of processing 398 million instructions per second, while having a modest 8 gigabytes of RAM and a large number of storage devices.

    Alone in the Void


    In May 1977 he was given the start of two major space research missions - were launched vehicles "Voyager 2" and "Voyager 1". Today, both probes continue to send collected data from those points in space where humans have not yet been. Where have not been artificial machines.

    At the end of August 2012, Voyager 1 sensors recorded a sharp decrease in the concentration of solar wind particles. This meant that Voyager 1 ended up in interstellar space. In 2013, Bill Webber, professor of astronomy, officially announced that Voyager 1 went beyond the solar system.

    Both Voyagers are almost identical and use three computers: the flight data processing subsystem, the command processing subsystem, and the angular orientation and articulated joint control subsystem. Together, they correct the probe’s route, direct the antennas toward the Earth, and control research tools, such as cameras. True, the cameras were turned off and not used since the probe completed the passage past the planets of the Jupiter group.

    After 40 years, spacecraft software is still operational. Suzy Dodd, project manager for the Voyagers program, said the software was updated during the flight, but NASA did not fundamentally change or delete anything.

    / photo Dusty Reichwein CC

    The probes have only 70 kilobytes of memory, which is why the program code has to be replaced at various stages of the mission. “For example, this happened 18 times during the passage of Jupiter,” says Ed Stone, a program scientist. And once, in 2010, distorted data began to come to Earth. The problem was in one bit, which switched from zero to one - the program was restarted and is still in operation to this day.

    NASA expects the maximum lifetime of probes and software to be 48 years: from 1977 to 2025. By 2020, scientists will shut down some spacecraft systems, but they will continue to “communicate with the Earth” anyway until they send their last message in 2025. At this point, one of the oldest computer programs will cease to function.

    Public input


    Similar stories, when the old program, written several years ago, continues to be actively used, are also found among enthusiastic developers. And this is not surprising, because the smaller the user base of the program, the greater the likelihood that the code will work "forever" and without changes.

    For example, in one of the threads on Hacker News, developers shared their own stories. A user with the nickname Byuu said that the whole smwcentral.net community uses the xkas cross assembler, which he wrote in 2001.

    “I added just a few small patches in early 2004 and released the final version of v06,” says Byuu. - I did not hope that someone would seriously use my decision. I did it for myself, but put it on the network. ”

    According to him, this is a code with a length of 1,500 lines without comments and indents. No documentation is attached to it. Each user encounters different bugs that community members learn to "circumvent." It all turned into a vicious circle - people used xkas because everything was written in xkas.

    A little later, enthusiasts began to write their own versions of assembler, offering backward compatibility for unobvious solutions to the original program. “I am very ashamed of the fact that so many people are stuck in this cycle of mistakes, but I can’t do anything about it,” Byuu concludes.

    Buro9 also shared a story. According to him, the oldest code that he wrote, and which still works, is a certain system for internal use by a recording studio created in 1997.

    “I'm still getting emails asking me how this or that function works,” says buro9. “And I have no idea, it was PERL.”

    Another solution is software for project management, written ten years ago, which is used by UK banks and some engineering companies. According to the author, it does not have Internet compatibility and has never been updated. Since such organizations manage twenty-year projects, then most likely this program will work for at least a dozen more years.

    Perhaps this is the main reason why many systems are still functioning. After all, it’s often impossible to upgrade to a new version of the software or change the platform completely — it’s too laborious or, on the contrary, not worth the effort and money.

    However, there are people like Sparkler Filters with their IBM 402 who follow a simple and well-known rule: “It works - don’t touch it”. Thanks to this, we can observe such amazing decisions that have passed through the years and have not lost their functionality.

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