Intel 80486SX

Intel's i486SX was a modified Intel 486DX microprocessor with its floating-point unit (FPU) disconnected. All early 486SX chips were actually i486DX chips with a defective FPU. If testing showed that the central processing unit was working but the FPU was defective, the FPU's power and bus connections were destroyed with a laser and the chip was sold cheaper as an SX; if the FPU worked it was sold as a DX. Computer manufacturers that used these processors include Packard Bell, Compaq and IBM. Back in the early 1990s, common wisdom held that it wasn't advantageous for most users to have a FPU. Thus, many typical household applications already in existence like word processing and email were designed specifically to avoid using floating point operations. When floating point operations needed to be performed they were still performed, but not in hardware; instead the operations were usually facilitated by transparent software emulation.