INT 2A - PC/TCP PREDIR.EXE - GET CONFIGURATION STRINGS
        AX = FF95h
        CX = what to get
            0000h ??? (returned pointer to "C:\COMMAND.COM")
            0001h spooling program
            0002h ???
            0003h spool file name
            0004h swap file name
Return: AX = status
            0000h successful
        BX:DX -> ASCIZ configuration string