xenix vi and Tmp files

[Robert Swirsky]

I'm having vi problems. 
There's a file I have that is 338767 bytes long. I have edited this file
dozens of times in the past. Today, I tried to edit it with vi and I get
the message "Tmp file too large."

I have 55000+ blocks free on the device that holds the /tmp directory,
so there should be plenty of room. I checked the permissions on /tmp and
it is drwxrwxrwx, so that's not the problem.

Does anyone know what would make vi think it's out of /tmp space when
there seems to be plenty? ex, which is linked to the same program, gives
a similar complaint. The only thing I can think of is that the "Tmp file..."
message has *nothing* to do with the tmp directory.

Thanks!