A compatibility card is an expansion card for computers that allows it to have hardware emulation with another device. The most popular of these were for Macintosh systems that allowed them to emulate Windows PCs via NuBus or PCI. Apple Computer made many of these cards (including a compatibility card for the Apple IIe. Later, Orange Micro made them, but by the end of the 1990s, greater application availability and the lack of expansion slots on the iMac made such cards obsolete. Besides PC compatibility cards, others existed, such as the 3DO Blaster for PCs.
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Compatibility card Wikipedia(Text) CC BY-SA