Brings back memories. If I recall correctly, when you had this turned on, files would get a hidden extension of .1 .2 .3 etc. And you could specify how many revisions to keep around? I also recall on our system, most of the time this was turned off because disk space was so precious. But I do recall this feature saving my bacon a time or two...

Yep! It goes up to 32k by default, but you can limit it:

"The /VERSION_LIMIT qualifier for the CREATE/DIRECTORY, SET DIRECTORY, and SET FILE commands lets you control the number of versions of a file. If you exceed the version limit, the system automatically purges the lowest version file in excess of the limit. For example, if the version limit is 5 and you create the sixth version of a file (ACCOUNTS.DAT;6), the system deletes the first version of the file (ACCOUNTS.DAT;1). To view the version limit on a file, enter the DIRECTORY/FULL command. The version limit is listed in the File attributes: field."

OpenVMS Manual http://h41379.www4.hpe.com/doc/731final/6489/6489pro_006.htm...

I thoroughly enjoyed using DCL (Digital Command Line -- the VMS shell) and VMS (with the wall of documentation, like http://www.pkl.net/~matt/photos/machines/tn/pict0157.jpg.htm...). It always felt structured and orderly, unlike UNIX systems, which are more "organic". :) (I love UNIX too!)

This wasn't unique to VMS. Symbolics Genera had this capability. ITS, VME-B, and I think TOPS-10, also had numbered file versions.

Fair enough. My computing career started in the nineties on VMS at the Help Desk of Brandeis University, my work-study job.

I wonder what the VCS landscape would have looked like if git was being developed on top of VMS rather than Linux...

filename.c;1 filename.c;2 filename.c;3

git checkout filename.c;2

The original MacOS was also supposed to copy this revision capability -- imagine, built in document versioning. Versioning was surfaced in the API but apparently never implemented. Had to always be set to 0 (1? long time ago).

This always caused me to run out of disk space (my quota was 512k).

Any idea if it was a full copy of the files, a rolling diff, or a Copy On Write at the block level?