>> I am trying to write a device driver for SCO's Xenix SYSTEM V release 2 > Assorted lore -- ammended Copyseg in reality takes far pointers, correct invocation would be more along the lines of: copyseg((faddr_t) source, (faddr_t) dest, (unsigned) cnt); where a faddr_t is a char far * (typedef in <sys/types.h>).