Sharp EL-5150 Scientific Calculator from 1985 

Thank you and congratulations, as usual Calculator Culture produces an excellent video which includes the main facts and performances of the calculator. As he indicates it in conclusion, he did not speak about the statistical functions of SHARP EL-5150 which, as for many calculators, are one or two variables. But it should be noted that this excellent calculator offers a feature rare among most manufacturers (excluding SHARP calculators which will follow) concerning the possibility of entering the data frequency. This frequency is not necessarily integer and therefore allows all sorts of weightings. Thing sometimes impossible on other machines of the same era. I agree with his conclusion, this calculator surprising by the layout of its keyboard turns out to be a reliable and precise tool. The layout of the functions is in fact explained by the automatisms of the different modes of use which mutually prohibit certain functions in order to guarantee the accuracy of the calculations and avoid many operating errors or ambiguities in the interpretation of the results. For example, the Z Y X W V and U registers are inaccessible in STAT mode to avoid any error in the statistical functions, but their content is retained when leaving this mode, which means that the statistical data previously entered in STAT mode may be easily used later by an AER expression. Returning into STAT mode doesn't erase the previous acquire data and allow data addition or restart with a new set of entries. The capital letters (from A to Z) are global registers that can be modified by the STO and RCL instructions. Register M can also be modified by M+ or M- and read by RM. It's a small detail, but user variables whose name is in lowercase, and which can contain up to 7 characters (letters, numbers or Greek symbols) cannot be assigned or read by STO and RCL but the assignment simply uses the = sign like in BASIC. This allow replacement of the default ANS 1=, ANS 2=, ... with meaningful user customise labels. As for the statistical mode, any result from the evaluation of an AER expression can be used for further and chained calculations or transmitted to another AER expression via the global registers (the capital letters). I particularly appreciate the display modes which can be modified at any time and indicated by the FIX SCI and ENG annunciators. Obviously, and as Calculator-Culture say it in his conclusion; this machine lacks some advanced functions which, although it has a lot of memory, cannot process tables or matrices; It also lacks the indirect addressing of the registers, connection to any printer, ... ... and a whole bunch of other functions that will only appear in our pockets later. Let's not forget, this is a machine that dates from 1985.

1:05 Replacement displays for the EL-5100 are now available, thankfully. I have two EL-5100 calculators in otherwise beautiful condition that have succumbed to the dreaded screen bleed. I will get around to installing replacement displays one day. It's a shame that the new displays don't retain the yellow filter of the original, as I always found that quite charming.

I like this Sharp keys design. I lived long time with my first calculator Sharp EL-503. (It was still working when I checked it last time.) First battery replace after 11 or 12 years of daily use. 🙂

@2:18: Small correction, the characters are 5x7 pixels, not 4x7 as you stated. Since this is an 80s device and we're 40 years on we can actually see and count the pixels on your excellent video!

Thanks for another interesting video :)

Typo at 8:05, y = x^2 - 9 definitely isn't 1.34. You're missing the coefficient of 5 in front of the x. Great video as always, I haven't seen many Sharp calculators for sale aside from the G850s from Japanese ebay.

Sharp did a few good calculators :)