GetCHS proc mov AX, LHA xor DX, DX mov BX, SPT div BX inc DX mov SECT, DL xor DX, DX mov BX, HPC div BX mov CYL, AL mov HEAD, DL ret GetCHS endp
See: CHS conversion
... The symbol <math>\pm \sqrt {b^2-4ac}</math> in the formula should be understood as "either of those element(s) of the field whose square equals b2 - ...