VInitializeTape - checks whether the tape drive is on-line.
VInitializeTape checks whether the tape drive is on-line and rewinds the
tape if it is on-line.
0 - work successfully.
2 - read error.
7 - "VIEWNIX_ENV" environment variable not set.
101 - tape drive is not on-line.
The environment variable "VIEWNIX_ENV" must be set to the 3DVIEWNIX
system directory. The file "TAPE_PATH_NAME" or
"$(VIEWNIX_ENV)/FILES/VIEWNIX_ENV" should contain correct information
(see Appendix C).