I have built a basic scientific calculator using the C8051F020, an LCD and a keypad (hobby project). Code and schematics can be found here:
@Danno, thanks for sharing your work!
Here is a video of two calculators I have built, one using a C8051F020 and LCD and the other a C8051F120 and GLCD:
For the C8051F020 I wrote the code in C and used the floating point library. For the C8051F120 I wrote assembly routines to add, subtract, multiply and divide two 16-bit integers.
I would like to write C code to perform arithmetic operations on decimals and build up a scientific calculator that eventually does powers, trigonometric functions etc.
This is a hobby project and I want to write all of the routines and not depend on libraries. Does anyone know of resources that would help me with this? I have read Clive Maxfield's excellent "How computers do math" that explains integer math and am now looking for material on floating-point routines.