In contrast to the F-30 and other Cheap CASIO and Cheapest CASIO models introduced previously, the CASIO CFX-400 is a superb, highly functional wristwatch released in 1985.
What makes it so highly functional is that it has a whole scientific calculator function in a wristwatch.
This is a great example of how CASIO has evolved from a calculator manufacturer to a digital wristwatch manufacturer.

"SCIENTIFIC CALCULATOR" is proudly written at the bottom of the LCD screen.
The price tag said “Binary, octal, decimal, hexadecimal, mutual conversion and calculation function” + “26 function calculation function”.
Too much!

As you can see from the photo, multiple functions are assigned to a single key, making it impossible to operate without an operation manual.
Moreover, the size is a little smaller than the current Data Bank series, so I thought it would be very difficult to operate, but the response of the operation panel is surprisingly good and delicate, and I was able to perform calculations without making any mistakes.
I love the feeling that technology has been put into this small body.

In this day, it would never have passed the planning committee and would never have been commercialized.
The 1980s were really a free era!

As one would expect, the product did not sell well in Japan at the time, and is now rarely seen in online auctions and the like.
Although they are consistently sold at overseas auctions, they are priced at ridiculous prices.


There is also a low-priced (?) version of CFX-200 that uses buttons for the control panel.
This one has too many 24 buttons!

I think CASIO is really a nice company.