Oct 022012

It’s not every day that I can actually add some new information, however trivial, to the “interwebs”. But today, I received a question from a calculator enthusiast. He wanted to know the meaning of a mysterious “BM” or “BN” logo that he found on the back of a vintage Sharp pocket computer:

I have seen this symbol many times before. I thought I knew what it meant but suddenly, I was stumped. What was it? A standards organization? A quality logo? Something else? Google was of no help either; I was searching high and low but couldn’t find anything even remotely resembling this strange sign.

Then I looked at my collection of scanned calculator manuals and sure enough, on the cover of a vintage Casio manual, I found it. Same logo. It even had some text next to it, but it was not legible. So I started searching my library of paper manuals.

Much to my disappointment, while the logo was present on a few of them, it was not much more legible than the one on the scanned copy. Eventually, I came across a manual that contained a semi-legible version:

So this is it. The logo reads, in case the above is not sufficiently legible:


Recognized by

Mystery solved. And while I nave no clue as to why information about this once prevalent logo is not readily available online, I can confirm that searching with the above full phrases on Google reveals nothing relevant (with one exception; searching for the strings “BM MARK FOR” and “HIGH QUALITY” yields one relevant hit, a scanned PDF copy of the Canon Palmtronic F-7 manual from the Web site of Katherine Wasserman). Well, I guess that is going to change now.

 Posted by at 3:37 pm