In the early 1990s, Orange Micro introduced what were described as "DOS compatibility cards". This was a concept first introduced in the Mac286 by AST Research, for which Orange Micro had purchased the rights. These cards essentially consisted of an entire PC on NuBus or PCI cards. They contained enough hardware in order to run PC software such as DOS and Windows at native hardware speeds: notably, an Intel-compatible CPU, RAM, sound cards, and video chipsets supporting CGA or VGA. Some hardware, such as disks, printers, modems and network interface cards, were emulated in software.