Complex sentence: IrisVision was an expansion card developed by Silicon Graphics for IBM compatible PC's in 1991 and was one of the first 3D accelerator cards available for the high-end PC market.
Split into simpler sentences: IrisVision was an add-on card developed by Silicon Graphics for IBM compatible PC's in 1991. Technically speaking, it was one of the first 3D accelerator cards available for the high-end PC market.