The Unisonic 799 (799-A) is a basic scientific calculator, with an eight-digit green flourescent display. It measures 3.5" wide by 6" high. There is a ninth display column on the right side of the display that has overflow, minus, and memory indicators. The machine is powered by a four AA batteries with an AC adaptor plug at the top left of the case. Power consumption is listed on the back at 0.5 Watts. It has a classic Unisonic stainless-steel covered case, although the case itself is black plastic. The machine weighs approx. 6.5 oz. without batteries. There is an instruction label on the back of the machine that has the keystrokes needed for six example problems.
The machine has an on-off switch and a DEG/RAD switch. The second-function key, marked F, is a red color. The function keys are blue and marked as follows: X/Y (X exchange with Y), X/M (X exchange with memory), X raised to Y, C, CM (clear memory), DR (degrees to radians), MR (memory recall), -, divide, +, x, M+, +/-, and =. The only function key that has a second function is the +/- key, whose second function is pi. The numeric keys are white, and their second functions are (from 0 to 9): 1/x, e to x, ln x, log x, sin-1 x, cos-1 x, tan-1 x, sin x, cos x, and tan x, with the decimal point key having the second function square root. The machine utilizes a Rockwell calculator IC which provides only basic scientific notation. There is no provision for scientific notation in this machine. I believe it to date from 1975, based on date codes inside the machine.
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