This is the original contents of M100SIG.ZIP. If the file timestamps are to be trusted, the zip was created in 2002, and the contents appear to have been assembled in 1996, and the last update to the contants other than the act of assembling it was some unknown time before that.
The zip file in this release is the original M100SIG.ZIP simply for reference, and the "source" zip provided by github is identical except for the addition of the root directory README.md and LICENSE.txt. The original zip was simply unpacked and committed.