INT 21 - FLU_SHOT+ v1.83 - INSTALLATION CHECK AX = FF0Fh Return: AX = 0101h if resident Notes: FLU_SHOT+ is an antivirus/antitrojan program by Ross M. Greenberg and Software Concepts Design the "PSQR/1720" virus calls this function to determine whether FLU_SHOT+ is present SeeAlso: AX=FF10h