I/O Library:

Only complication is seeks. Version 7 seek is different from version 6.
This is handled by means of a LSEEK routine that under V6 breaks up lseeks
into one or more V6 SEEK's.

The version 7 lseek is trivial.

For version 7 system do:

mv lseek.s v6lseek.s
mv v7lseek.s lseek.s
as -o lseek.o lseek.s
ar rv -lf lseek.o
