neil wrote: > If I recall right Microchip did not invent the PIC processor. It was > available from > Intersil before there was a Microchip. the 16x54 series was available in > MOS technology and used in many early cable TV boxes. No. General Instruments developed the original PIC processors in the 70s. Intersil was not involved. GI spun off their microelectronics group as Microchip Technologies. So Microchip definitely does own the PIC. However, what does this ownership mean? Clearly no one else can use their trademarks (including "PICmicro") for a competing product. No one else can copy their copyrighted software, data sheets, and documentation. No one else can make exact copies of PIC dice (the actually silicon layout). But beyond that, the only thing preventing cloning the PIC architecture is patent law. Microchip does have some patents relating to PICs, but they are very peripheral to the architecture. For instance, some of their patents cover the way that they implement code protection and brownout detection. Both of those things can be done differently without seriously compromising compatability. Even if they had some patents on the CPU core architecture, they would have long since expired, since there were NMOS PICs in the 70s that had the same basic architecture. For my own part, however, I wouldn't use a PIC clone without doing an extremely thorough evaluation. The PIC isn't an extremely compex part, but it is complex enough that it would be easy for a would-be cloner to make mistakes and wind up with a not-quite-compatible part.