To be fair, Sony made a bit of a mess of the backwards compatibility feature of the PS3. Initially the Playstation 3 shipped with the main processing unit from the Playstation 2, called the Emotion Engine as part of the SKU which meant that in effect, you were buying a PS3 and PS2 in one box, providing universally compatibility for all Playstation games. This feature was present in Sony's Playstation 2 for PS1 games, and it would have provided a good advantage over its main competitor Microsoft's Xbox 360, which only has limited backwards compatibility of original Xbox games. Presumably to cut costs to make pricing of the PS3 more competitive, Sony dropped the Emotion Engine from future SKUs severly crippling support for backwards compatibility.
It would appear that things could be about to change however, as it seems Sony have filed a patent for technology enabling the emulation of the PS2 Emotion Engine on the Playstation 3's beefy Cell processor.
In the world of emulation, there are two ways such a thing can be done, either all of the code to be emulated must be translated to understandable code before processing, or the system must be provided with a library for which to reference for how to process the emulation code during processing.
Sony developed a way to translate instructions from an Emotion Engine chip into chunks that can be referenced.
Figure 2 from the patent is a schematic drawing of how the system works. Figure 3A is a drawing of the PlayStation 2ís chipset. Figure 3B is the emotion engine. Figure 4 is where the whole story gets interesting! Itís ďan example of a host system based on a cell processor that may be configured to emulate the target system.Ē The target is figure 3B, the Emotion Engine.