My first Unix was v6. It had seek() but no lseek(), which was introduced in v7. We converted several programs to use it. The tape archiver in v6 was called tp.

My first Unix was v6. It had seek() but no lseek(), which was introduced in v7. We converted several programs to use it. The tape archiver in v6 was called tp. I never used tap, which was earlier. Tar was introduced in v7. It was a complete re-write and used a different on-tape format.