One of the conundrums facing console makers as they eye a new product launch is the issue of backwards compatibility. Consumers love it and have come to expect it. As console architectures change, however, providing complete backwards compatibility has become a more daunting task for the likes of Sony and Microsoft. Sony in particular has committed to providing PlayStation 3 buyers with the ability to play their old PS2 games, and is apparently going to do so by including PS2 hardware in each new console.
With the PS3, Sony is switching chip architecture. Sony’s choice of the IBM Cell processor means that the PS3 is using a different instruction set architecture (ISA) than that of the PS2. Given the complexities involved in programming for the PS3, ensuring software emulation works seamlessly and transparently for users is no small task. The company has committed itself to a November launch, a time frame which may be forcing them to take a shortcut on the issue of emulation. In order to launch the slimmed-down PSTwo, Sony put the Emotion Engine CPU and Graphics Synthesizer (GPU) onto a single chip. It’s not unlikely that the company has squeezed additional PS2 functionality onto the chip, which would in turn make incorporating it into the PS3 a relatively trivial and inexpensive matter.
Reports are that the rumored hardware-based PS2 compatibility will be removed from shipping PS3s once the software emulation is perfected. That could leave PS3s with differing levels of emulation ability depending on whether they are using hardware or software emulation. (Of course, Sony could always turn off PS2 hardware inside a PS3 with a downloadable patch.)
Choice of hardware and software emulation aside, this is an easier problem for Sony to solve than Microsoft. Having much of the PS2’s functionality on a single chip makes the hardware situation is a bit simpler for Sony. Attempting to cram a Pentium III and NVIDIA graphics chip from the original Xbox into an Xbox 360 would be a more expensive (and complicated) proposition for Microsoft. As a result, 360 owners are left with partial backwards compatibility for their Xbox titles, with the list of playable titles continuing to grow slowly.
If Sony does end up including PS2 hardware with each PS3 sold, full backwards compatibility could be an additional selling point for the console in the battle for market share. Would it also mean we’d be able to play Castlevania: Symphony of the Night on it?