On the 64-bit AIX, HP-UX, and Solaris platforms, the V6 and V6TAPE read-only engines provide read-only access to your Release 6.12 data sets. See SAS Language Reference: Concepts for more information about the compatibility of V6 files with SAS 9.1.
With the Tru64 and Linux platforms, you still have read and write access to your Release 6.12 data sets. For more information about compatibility issues, see "Accessing SAS Files across Compatible Machine Types in UNIX Environments" on page 108.