Well, it's rather difficult to say that there's really a `history' that goes along with this file, but I thought this might be interesting to some.
What caused me to find this? Sheer luck, I think. I had this old crappy 486 motherboard and I had misplaced some jumpers. I didn't know who made it or where they went, and I didn't have a manual. So, my plan was to take them all off, and then put them all back, randomly (but not so as to break the thing). Of course, that didn't work. I finally did get the thing to boot to the board identification string. I wrote that down and went about searching. I don't believe I found anything. I was searching (what else?) Google for strings such as "motherboard jumper settings" and other similar things. After a LOT of searching, I eventually came across a URL that was something like (from memory) http://www.geocities.com/~checksum32. In it was a file called th99free.tar.gz that was about 10MB. Being on a dialup modem, this took a while. Buy my! Was it ever worth it! I got the board working and was happily on my way.
Later on, I made a post, to a list I'm on, looking for mirrors. I got one or two, but that's it. Over time, I've accumulated all the mirrors listed here.
Of course, I'd always be happy to hear about new mirrors. I'll let you figure out how to contact me, though :-) .