INT 12 C - CPI-standard virusA program which attaches itself to other programs for the purpose of duplicating itself. Viruses often (but not always) contain harmful code which is triggered by some event, after a certain number of reproductions, or on a specific date. See also worm. - "FRIEND" CHECK AX = 4350h BX = 4920h CX = AB46h DX = 554Eh Return: if friendly (not to be infected) CX:DX -> ASCIZA NUL-terminated ASCII string. The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h. Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. identity code (changes yearly) SeeAlso: INT 13/AX=EC00h"VIRUS",INT 13/AX=5001h,INT 21/AX=0B56h