I downloaded this MAC OS 10.2 instalaltion CD from torrents and they say it is for iMac G3 500 MHZ including (I have 500 Mhz version).
Regarding Linux Ubuntu, here is what I get when use command "fdisk -l":
P.S. BTW, I thought Linux should mount partitions automatically, especially when they are FAT32/NTFS partiotions (which is my case because I took this HDD from my old PC computer for testing this mac)
You're absolutely sure that it was the retail disk that was downloaded right? Could be a bum torrent.