typedef struct _Dev_Hdr {
        struct _Dev_Hdr _far *dev_next; // ptr-next driver
        unsigned int dev_att;   // driver attributes
        void (_near *dev_strat)();  // strategy entry
        void (_near *dev_int)();    // interrupt entry
        char dev_name[8];       // device name
        int dev_resv;           // reserved
        char dev_letr;          // 1st drive letter
        char dev_units;         // number units
        } Dev_Hdr;

