The Ace clones from Franklin Computer Corporation were the best known Apple II clones and had the most lasting impact, as Franklin copied Apple's ROMs and software and freely admitted to doing so. Franklin's response was that a computer's ROM was simply a pattern of switches locked into a fixed position, and one cannot copyright a pattern of switches. Apple fought Franklin in court for about five years to get its clones off the market, and was ultimately successful when a court ruled that software stored in ROM was in fact copyrightable in the US. (See Apple Computer, Inc. v. Franklin Computer Corp.) Franklin later released non-infringing but less-compatible clones; these could run ProDOS and AppleWorks and had an Applesoft-like BASIC, but compatibility with other software was hit-or-miss.