The vast majority were downloaded. A few I got when I exchanged compilation DVDs with someone in Finland in 2006 and 2009 (I uploaded the images on those to BetaArchive back then and they've made their way onto various other sites). The only ones that I have that were installed from images I dumped from original media that hadn't been previously shared were LynxOS 4.0 and MaxOS Linux (not to be confused with macOS, it was an obscure early-2000s commercial Slackware fork from a company that was semi-local to me; the CD was given to me back then by somebody at a long-defunct local computer store).