A Unique Display Makes An Unusual Clock

Do you know the clock speed of the computer you’re reading this article on? Maybe Hackaday readers are more likely to reply “Yes!” to that question than the general public, but if there’s a takeaway it’s that for most computer users their clock speed is now an irrelevance. It’s quick enough for the job in hand and that’s all that matters. This was not always the case though, and a few decades ago the clock speed of a PC was its major selling point. Beige boxes would have seven-segment displays lit up with the figure, and it was an unusual example of one that [Ken Yap] used to produce a clock that he believes is one-of-a-kind; unless by some slim chance somebody else has rescued the same part.

The displays were hard wired without any signals from the processor, and what makes this one unusual is that as well as having a couple of digits in yellow it also sports a segmented “MHz” in red. This would have been quite a big deal on your 486 back in about 1994. To make a clock from this unpromising start required a little creative thinking, and he manages it by using the “M” and the “H” digits to represent minutes and hours, and displaying each figure in turn. The display is wired on a piece of protoboard with an STM8 dev board, and yes, as you can see in the very short video below the break, it does tell the time.

Custom displays are more usually seen in the world of LCDs than LEDs, so this one remains a rarity on these pages. Happily there are projects out there in which people spin their own takes on the idea.

28 thoughts on “A Unique Display Makes An Unusual Clock

  1. “This was not always the case though, and a few decades ago the clock speed of a PC was its major selling point.”
    Now also it’s. Only for those isn’t, who lived in a box until now. Like cars horsepower or so. Many people doesn’t care about clock speed, but if you need to choose between PC’s, it’s one of the major factors.

    1. Clock speed may be a selling point, but it has little to do with relative computing speed when comparing CPUs of different generations or (internal) architectures (AMD vs Intel) or cache sizes or (for those few purposes where it matters) core count. And external factors can affect the effective computing speed as well, such as memory clock speed and timings.

      If I want to compare the speeds of processors, I’ll look at perhaps PCmark numbers or some other computation speed benchmark.

      1. One slight problem with using PCmark (compiled with an Intel compiler*) to benchmark anything other than Intel CPU’s.
        * https://en.wikipedia.org/wiki/PCMark#Controversy
        * https://en.wikipedia.org/wiki/Intel_C%2B%2B_Compiler#Reception “The FTC settlement included a disclosure provision where Intel must: publish clearly that its compiler discriminates against non-Intel processors (such as AMD’s designs), not fully utilizing their features and producing inferior code.”

      2. My last post has urls in it, so delayed until a human reviews it. Lookup “benchmarksmanship”, PCmark (compiled with Intel’s compiler) is only good for comparing Intel CPU and GPU performance, and pretty much nothing else related to CPU’s and GPU’s. If intel CPU/GPU is detected use optimised algorithm, if not intel CPU/GPU, use worst performance algorithm available. search for “FTC intel compiler discriminates against non-Intel processors”

  2. Just the abuses of the English language rules for syntax and grammar in the article are painful enough. I shall refrain from commenting about the quality of the same in the comment section.

    1. I’m a grumpy old coot myself, but sheesh, your (sic) going hard at it there.

      Nice looking perfboard assembly there, and an interesting way to use the part.
      Never too many clock posts.

    2. Why, I can’t say I remember you from the ranks of my colleagues during the time before I started working for Hackaday, when I spent many years working for the Oxford Dictionaries.

  3. I remember having one of those 7 segment displays on my 486, but it didn’t have the MHz segments. It was a 3 digit model. I upgraded from 25 to 80 MHz, and when it didn’t change automatically I dug in to figure out why. I had to manually and randomly flip jumpers until I had all the right segments on. That was annoying. Also I went ahead and changed it to 100 for the hell of it. :D wishful thinking I suppose.

  4. Well, that’s a creative re-use of M and H. I guess if an alarm clock was made, the z could be used for the snooze timer!
    Definitely a rare LED display. Like others, I’ve seen/had old computers with 7 segment and jumpers to configure the right speed, but never with Mhz. Hard wiring kind of defeats the purpose of having an indicator, especially for those who dared venture into the world of over clocking. But, just like 7 segment house number signs, it’s nice to see colourful bright numbers. I guess the way the article starts about the speed of your computer is kind of moot, since it’s not the speed of the computer but slowness of the bloatware that dictates frustration. But, that doesn’t matter, this project is possible because Ken Yap saw M H and thought of a new use for them! Perhaps put the display in a mirror to make the z look like an s?

  5. I built a lot of different PCs in the 1990’s, and I can honestly say that most of them had something similar to this display, though I don’t remember seeing one quite like this one.
    Nice clock build, and clever re-use of something that has very little re-use value.

  6. I always thought those displays were ridiculous and sort of crass. Sort of a conspicuous consumption sort of thing to have the clock speed on a silly display. I suppose the main purpose was for you to see a higher number on someone elses machine and then start itching to spend money on an upgrade.

    Clock speed certainly doesn’t matter these days. Unless you are running something other than the usual 3.5 Ghz clocked processor, now it is all about how many cores at that top speed. If you haven’t upgraded your desktop in 10 years or so and are still running something at 2.5 Ghz, then yes, it matters.

    I’m sort of glad to say I never had a case with one of those gadgets, but nice to see this one put to a creative use.

    1. > Clock speed certainly doesn’t matter these days. Unless you are running something other than the usual 3.5 Ghz clocked processor, now it is all about how many cores at that top speed.

      Friend, if you have a 8-core running at 2.5GHz and a 4-core running at 5GHz you’d reconsider this argument, especially considering most applications only use a single core. Clock speed still matters a whole lot and simple benchmarks demonstrate this.

      I don’t know how 3.5GHz is “usual”, either. I haven’t had a desktop CPU slower than 4GHz since 2014.

        1. the person probably had (or looked-up) the 4GHz i7. maybe they ran it at 3 or 5GHz for a day — who cares. the claim might as well be about sub-ohm vaping or wine pairing skills.

    2. On the machine I had with this kind of LED panel, I switched out the jumpers to say “HI” and “LO” fairly early on.

      Not like the numbers (as configured by the seller) had much correlation with the speed difference between turbo and not.

    3. Actually, I think it’s just cool because when you press the turbo button the displayed number changed — the fan speed adjusted, too haha. No jealousy or “want-to-have” emotions were ever created because of this. Then again, I was a kid, and maybe I am just not that type.

      The reason was in theory so you could use software (i.e., play games ;) that would run too fast on modern hardware. But I was always told that it didn’t actually reduce the clock speed, and instead, would disable the cache or some other memory function.

      In other words, it was cool but pretty useless all around :)

      Maybe to compete, you should have just taken a calculator, and type in a higher number and glue that in front of your tower, depending on whoever was about to visit ;)

  7. Apropos of nothing really, I have to say that the STM8 chips are criminally underappreciated. I’m doing a project right now for a miniature xmas tree. They have plenty of pins, a small size, and you can power them off batteries very easily.

    They really need more love amongst hobbyists.

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