You can upgrade the Macintosh Centris 610 or 650 with an FPU, but Apple doesn’t provide or support such an upgrade. You must rely on third-party companies who can remove the 68LC040 from its socket and replace it with a 68RC040. Since Apple doesn’t intend to offer an upgrade, we can’t guarantee that the processor will remain a socketed component.
There aren’t very many compatibility problems with non-FPU systems. While the addition of an FPU allows certain types of applications to execute faster, these applications tend to be more technical in nature. Business applications — such as spreadsheets, databases and word processors — don’t require an FPU to run.
Most applications check to see if there’s an FPU present. If one doesn’t exist, they emulate the floating point instructions in software. There are a few applications that expect or require an FPU. These applications will present problems and we anticipate most software developers will revise these products.
The Centris line is a weird, sad story in Mac history.