IBM made a surprise comeback to the desktop PowerPC market yesterday, when it was announced -- albeit by Apple -- that Big Blur would be fabbing PowerPC 7400 (aka G4) CPUs. It's not yet clear whether this is simply a little arm-twisting on Apple's part to get IBM to produce extra chips, or whether this is a commitment on the IT giant's part to the G4. Back in July 1998, IBM pulled out of its partnership with Motorola in the development of PowerPC chips for the desktop PC market, choosing instead to concentrate on processor for the server and embedded markets. At the time, one of the reasons for the break-up was Motorola's advocacy of AltiVec, its vector processing system that rivals Intel's Screaming SIMD Extensions technology. Motorola was keen on competing with Intel, IBM felt that the technology didn't have much of a role in the markets it was interested so it had no interest in developing AltiVec or supporting it in its chips. And, lo, there was much wailing and gnashing of teeth at Motorola. With hindsight, IBM's move was ill-judged, but it certainly made sense at the time. By the end of 1998, the two companies had made up, and IBM was saying it could well support AltiVec at a future date, maybe, perhaps... What has made IBM's move away from AltiVec seem the wrong call is the company's more recent contract with Nintendo to create a PowerPC chip for the games business' next-generation console, codenamed Dolphin. Nintendo's console is being designed to compete with the Sony PlayStation 2, which is based on a Sony-Toshiba designed CPU, the Emotion Engine, which has its own vector processing system... So suddenly IBM needs the very technology it spurned 18-odd months ago. Part of the deal to get may well have centred on a commitment to produce G4 CPUs, which is great news for Apple, at least in the medium term. The Mac maker will have to wait until sometime in the first half of 2000 for IBM to get the volumes up. Getting IBM in on the act could also provide a boost to the G4's clock speed, provided the company applies its silicon-on-insulator process technology to the chip. Indeed, it could even offer parts at higher clock frequencies than Motorola, which could shift Apple's allegiance away from an operation it has already publicly criticised for its inability to ship sufficient volumes of 7400s. Now that is going to make for some interesting Mac market politics. ®