Don Jones

Tech | Career | Musings

Back when TV was first invented, their Cathode Ray Tubes weren’t terribly well-designed. They curved a lot, especially at the edges, making the picture at the edges useless. To compensate – to workaround – manufacturers buried the edges of the tube in the TV cabinet, so you could only see the relatively-flatter middle portion of the tube.

As a result, broadcasters had to be careful not to put useful information near the edges of the picture. This concept because known as overscan, meaning the tube was scanning its electron beam(s) across a larger surface than could be seen.

Improvements in manufacturing and electron beam control happened almost immediately, though, making overscan less necessary. Unfortunately, it was built into the broadcast standards by that point, and so everyone kept playing along. Today, overscan is completely and utterly meaningless in our world of readily-available, cheap flat panels. But overscan persists, with broadcasters identifying a “safe zone” for content, and more or less ignoring the “edges” of the screen. The problem is starting to fade as content shifts over to all-HD (which presumes a flat panel type of display), but it’s been an annoying problem for decades.

This should be an object lesson in not engineering workarounds as permanent solutions. If something feels hacky or kludgy, either don’t do it, or at the very least don’t bake it into a standard that will be difficult to change later.

For example, those early TVs should have been built with a circuit that took a non-overscanned image and shrunk it down to the flatter, reliable portion of the screen – with a switch that could turn that feature off. It’s not unlike the scaling modern flat panels can all do, in fact. That way, the workaround can be put into use, but the hack – overscanning – doesn’t get built into the broadcast standard.

We build workarounds every day in IT, but you should pay attention to them. Identify things that you know are hacky, and schedule them for a mental re-visit every few months. Decide if things have improved in other areas, and if the problem can now be solved in a better-engineered fashion. Kludgy scripts should be replaced with more sensible, maintainable, reliable solutions.

Don’t make workarounds part of a permanent standard!

6 thoughts on “Why Engineering Workarounds is Stupid

  1. I admit read the title for this blog post a few times and kept asking myself, “does he mean ‘Why Engineering Workarounds ARE Stupid?'” and wondered if it was a play on words – that the title itself was a hack of sorts. Then I realized I read it wrong. You’re saying the engineering (verb) of a workaround is stupid, not engineering-workarounds (noun) is stupid.

  2. jeff says:

    “Those early TVs should have been built with a circuit that took a non-overscanned image and shrunk it down to the flatter, reliable portion of the screen” — Perhaps this was not possible with the technology of the time.

    1. Don Jones says:

      It was. There were a few TVs made that way, actually, but consumer perception was that a bigger screen was better, and so they started doing overscanning to allow a larger “viewable” area.

  3. Chris says:

    I agree with your premise, but isn’t overscan how they first broadcast closed captioning, and data such as ceefax (in the UK)? It turned out to be quite useful actually.

    1. Don Jones says:

      No, they used some of the extra bandwidth in the signal allocation, but that was on top of overscan. Until we migrated off of analog OTA a couple of years ago in the US, overscan was still very much in use.

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