As I remember (And only because I am too lazy to reach 10 feet to my briefcase and lift it out
) but most of the non programmable calculators that have an alpha key have it for only one function!
This is to allow calculations in hexadecimal (base 16), Counting in hex is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1A, 1B, 1C, 1D, 1E, 1F, 20, 21....
Most Casio calculators will use the Alpha key to access an additional 6 memories (separate from the one used by Min & M+ ot M-) when it is in normal mode (screen showing dec) rather than in hex....
Hope this helps....
Regards,
Shuttlebus.
P.S. I have an all singing, all dancing £££Hewlett Packard 49G and 9 times out of 10 my £8 Casio FX570 (now about 12 years old) is quicker