A Blizzard 1260 card has only a 68060 processor on it whilst a PPC card has both a 680x0 series CPU and a PowerPC CPU on it. These two families of processors are closely related but have largely incompatible instruction sets. Thus you cannot run 680x0 code on a PowerPC CPU and vice versa. The Phase5 cards that have PPC on them as well as 680x0 CPUs used to have a very expensive spare CPU on them that was used for very little apart from the odd jpeg datatype until OS4. Now the PPC part becomes the main processor of OS code which before was the 68040 or 68060 CPU. (Me wishes I had enough cooling and money to own a PPC Blizzard card ))
