14 bytes for filename, and as I recall 2 for the inode in that particular filesystem, so a total of 16 bytes per directory entry. I'm not sure what the typical minimal disk space budget was, but assume as little as 5 MiB, e.g. 2 RK05s, so you had to make every byte count. On a student run computer center I started with the Logo Lab's surplus PDP-11/45, we considered ourselves very lucky to have scored the prototype CONS Lisp Machine's CDC SMD 80 MiB (unformatted) drive to run the system on. Note that the latest Haswell Xeon CPUs are getting up to a max of 45 MiB L3 cache....
What was much worse was that many programs just opened directories as files (which of course they are) and assumed that format, which caused more than a little pain when we moved to bigger machines and more sophisticated filesystems.
That was probably the one thing I hated the most in Solaris. We would have various platforms linked up together via NIS, which was synced against our Windows 2000 domain controller (I know, sounds horrible. But it did work surprisingly well in its day). For all the jokes about Windows security, even that supported longer passwords. And users did occasionally notice when logging into Solaris eg when they accidentally typoed as they hit enter. All I could say was "yes, I know it seems dumb. It's Solaris and we can't do much about that."
