Tech Flashback: KDS Converter/Measure/Calculator 5m (YS-5010ME)

There was a time in the not too distant past when, in order for something to be cool, it had to be electronic. Often this meant attaching an electronic clock or calculator to the side of the device for an immediate boost in its status. This sometimes resulted in rather quirky and silly cases of calculator crazies, such as the Calcu-Pen.

But there are other times it genuinely can come in handy, especially when it’s more than just your average $2 8-digit calculator from a variety shop.

The Product

The unit was given to me by a former family friend as they were clearing out their house. They thought that, as a piece of “vintage” technology, it might interesting. It certainly is! But unfortunately, since I’ve been so busy, it’s taken over a year to get online.

The unit seems to have been very well cared for in its time – possibly used infrequently. It came complete with its original box, printed in a very limited number of colours (red, black, orange and blue). The front of the box depicts a line-art image of the unit itself, branded KDS model YS-5010ME of 5m length.

The rear of the box advertises the features of the unit, which is made by Kyoto Measuring Instruments Corporation. I suspect this is now Muratec-KDS Corporation, a company that still produces measuring tapes today.

The side of the box again reflects the product details – CMC standing for “Converter Measure Calculator”. Catchy.

The unit has a decidedly grey-beige coloured body. Very tech, considering all the computers of the era came in similar colours. The branding is a label pasted into a slight recess in the case.

Information about the unit is moulded into the case, along with the width of the unit which is 3.75″. The unit is held together by screws, making this potentially serviceable and repairable in case of damage. Even the tape is secured into its retractor by a hooking mechanism allowing for the tape blade to be replaced.

From the top, we can see the red stripe carries over from the top through to the bottom panels, with the stopping device having a textured recessed button – a nice touch. A look at the bottom shows a similar amount of care in providing a notch to allow for easier opening of the protective flap that covers the calculator.


On the side, there is a hole for a lanyard strap and a battery door. Behind the door, two AG13/LR44/A76 cells are used to power the calculator, with the cells in series to provide 3V. On the other side, we can see the “unbreakable” stopping device plunger and the hook for the measuring tape itself.

In Use

From just handling the unit, the Japanese quality of the unit is apparent. Pulling out the tape is a smooth experience, with the tape feeling of high quality with clear markings and not crinkling randomly. The hook itself feels sturdy as well, despite the smaller width of the tape – the reason? The calculator consumes quite a bit of the front of the casing.

That being said, the unbreakable stopping device is a lot more positive than most average “friction locks” which merely drive a plastic wedge into the tape. The mechanism operates on a toggle – push to lock, push to unlock and doesn’t seem to do any damage to the tape with no obvious clinks or clanks as it is actuated.

Of course, the main attraction is not the tape, no matter how good it is. The calculator is accessible by opening the flap on the side. Comprised of hard-wearing glossy plastic dome-shaped keys, the unit seems to be able to take some abuse compared to rubber-buttoned counterparts. The label inside the lid offers guidance on conversion operations, with most operations fairly straightforward. Without using any of the orange keys, you can use the unit as a regular calculator.

But if you want to perform a conversion, it’s simple – just push the associated direction key, followed by the corresponding key for that conversion and the answer will appear. In the case above, I punched in 10, then hit the right arrow key, then hit in<->cm. As a result, it claims that 10 inches is equivalent to 25.4cm, which is correct.

If you really “torture” the device by converting multiple times back and forth, it’s possible to see some rounding errors, although generally they’re pretty small. Despite having fresh batteries, some of the segments on the LCD seem a little weak – a sign of its age and possible degradation in the components within, but at least it still works.

One potential downside is due to its plastic bodied nature, the unit could be subjected to harsh working conditions and the lid may be damaged. This unit, however, is still in relatively good condition (save for some engraving that had been photoshopped out).


The KDS Converter/Measure/Calculator is basically what it says on the box – a measuring tape with a unit converting calculator slapped on the side. While it genuinely served a useful purpose and is rather easy to use, the design seems to show the compromises necessary to integrate the calculator into the design including a reduction in tape width.

That being said, such a device is rare to see as it is well and truly obsolete despite still working perfectly adequately. This is because unit converter applications on smartphones are convenient and easy to use, but also because your average search engine and voice assistant is capable of doing the same. Furthermore, even the concept of a measuring tape is under threat, as newer laser-distance measurement devices are becoming popular and even some smartphones can use their inbuilt sensors to measure in three dimensions with fairly rough accuracy in any unit the user selects.

As a result, you won’t see any tradie walking around with one of these …

About lui_gough

I'm a bit of a nut for electronics, computing, photography, radio, satellite and other technical hobbies. Click for more about me!
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