The **Casio FX-110** is a vintage scientific calculator from 1977. It has a sleek design with a white plastic base and black top. The keys are arranged in the standard Casio layout that remained popular well into the LCD calculator era.

This model features a 10-digit blue vacuum fluorescent display (VFD) with an 11th digit to indicate negative exponents. It can display up to 8 digits in scientific notation. The plastic display filter provides a crisp, clean image. The on/off switch is conveniently located on the left side.

With four basic functions, reciprocals, factorials, square roots, exponents, logs, trig functions, pi, statistics and a 3-register memory, the FX-110 packs impressive capabilities into a very portable size. It measures 84mm x 152mm x 22.5mm and weighs just 144g without batteries.

Power comes from two AA batteries or via an AC adaptor. Batteries fit into a compartment on the back secured by a single screw. The quality and durability of the FX-110 is evident in its construction.

This model introduced the rare decibel conversion function to the line. It can also display sexagesimal measurements for degrees, minutes and seconds. Modes are switchable between degrees, radians and grads. However, the lack of parentheses, fractions and limited precision on advanced functions leave something to be desired.

Here are some notes on the logic and operation:

- Clear (C) deletes the input number, All Clear (AC) resets the calculator fully
- Overflow is suppressed, extra digits are ignored
- Constant function invoked by double press of operator
- No indication of memory use
- Negative sign pushes left, allowing 10 digits total
- Seven digit negative mantissas in scientific mode
- Overflow or divide by zero show error “E”
- Negative square roots error out
- Eight digit precision on scientific functions
- Can convert between decimal degrees and degree/minute/second notation
- Internal precision up to 11 digits
- dB key for decibel conversion
- No major bugs or quirks found

Overall, the FX-110 is a high quality vintage calculator with a very usable layout that stood the test of time. It provides basic scientific functions in a compact, durable, and attractive design. As an early Casio scientific model, the FX-110 represents an important milestone in calculator history.