50 digits precision handheld calculator is it achievable or not?

[Garth Wilson]

If you can feel the heat, batteries won't last long at all, and the unit certainly won't be able to run off the power it gets from a little solar cell in the front.

The number of digits is limited mainly by how long you want to wait for answers and how much memory you can allow for variables, stack cells, etc.. 50 digits would be no problem for a 1980 home computer except that it would be very slow and you might not have enough storage to be useful. The time required for addition and subtraction will be more-or-less proportional to the precision, but other functions will suffer far more from an increase in precision. The extent of my work in this kind of thing was to write 16-bit trig and log scaled-integer functions, so I'm no expert at this, but I can't imagine how long it would take on a given processor to get 50 correct digits for the ln(1+x) or tangent functions for example, as the infinite series converges prohibitively slowly, and suitable polynomial substitutes would probably be super long.