I'm using the PowerPC version and also using an iMac G3 with nearly a gig of RAM and a 40GB Hard Drive as well as a new WiFi card.
How do I install Minecraft on this machine?
Ok. What I have:
-Debian 7.5.xx for PowerPC architecture
-IBM P5 eServer (9131-52A)
-IBM 146GB 10K RPM Ultra320 SCSI hard drive (x4)
-Very little patience left
I have seen seen several threads here and elsewhere with instructions on installing the PowerPC version of Debian.