This is the Sharp EL-5001. It is similar in appearance to Sharp’s first programmable calculator, the PC-1201, but is not actually programmable. It was produced around 1977, is 6″ x 3″ x 1″, weighs 10 ounces and uses 2 AA batteries or Sharp’s EA-17E adapter. It also has 10 digit precision, a green VFD display, and algebraic logic. It has 37 functions and 39 keys. You might notice that it has a few sliding switches on it that you don’t normally see on a calculator. The switches on the lower right side of the calculator allow you to choose between using the calculators memory positions or parenthesis and the lower switch changes between Deg, Rad, and Grad.
The rotating switch on the top right side is unusual in that it controls a rotating display that corresponds to the six symbols shown next to it. Each time you rotate the switch the functions in the five windows will change and you can select them by pressing the blank buttons below. The far right window scrolls 1 through 6 to show which program you are currently set to. The programs that are available via the rotating switch are: Plot, Stat, EQ, Integral, Complex Numbers, and Vectors.
The Sharp EL-5001 Elsi Mate is a fairly difficult calculator to find. In mediocre working condition they sell for $70-100. But, if they are in excellent working condition then they can reach over $500.00.