SHARP EL-508A ============= I have bought this calculator. It's not new. I thought that it is from early 1980 but it seems to be from 1975 [1]! I gave got it because of my current nostalgic mood. When I was a pupil I had this calculator. Actually I used it through all my school years (at a basic school, at a hight school and ad the university). It definitively broke when I was already a Ph.D. There were several liquid crystals leakage (yes, if has a LCD) and some keys were worn off. I still have it somewhere. If I'm not mistaken the keyboard was produced on 1982 and I used it from about 1984. Now I have got an another one. It is almost intact. It is probably newer than my old one and was probably used only few times (there are no scratches and no dirt). There were two SHARP-branded batteries inserted. If I understand their labels the batteries were produced in 1986. Most probably these batteries are the original ones which were sold as set with the device. SO I can assume that the calculator is from about 1986, too. The serial number is 3V148088 but I have no idea how to read it. I remember that the factorial function (n!) was slow here. Well, the "69!" takes more than 5 seconds. That's not that bad (the goniometric functions are almost instant). Most probably I will not use it too often - I also have a solar energy based SHARP will identical functionality. It is also a bit smaller and I have a pouch for it. So it's a much better solution for situations when I want to use a small, simple scientific calculator. But I'm feeling very nostalgic when I'm playing with this one... References: [1] https://www.calculator.org/calculators/Sharp_EL-508A.html