Senva, 9 bytes 4 bytes
There is two ways to write this program, let's begin by the longest :
82.8--8-~
This stores 82
in the memory, substract 8, 8 again, 1, then display the memory as an ASCII char (65 is the ASCII code of A
). The cell's value is 82 - 8 - 8 - 1 = 65.
The second way is a little bit pernicious :
B,B_-~
This converts the 'B' character to its ASCII char code, substract 1, and then display it as an ASCII char.