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Well, I think we should wait until we actually see the beast before we start trembling. - The patent that has been referred to (#5,975,688) is just a design patent for a pair of internally connected electrodes on the cartridge body that press against a corresponding pair on the printer when the cartridge is properly installed. They do no more than turn on a light bulb. This is according to the patent. The purpose of this patent is to prevent a cartridge that is not meant for the printer from being inserted. I suspect that this patent has not even been been implemented. This is nothing new. HP received a patent for a similar idea in 1995 (#5,411,343). It appears that the patent that we should take an interest in is #6,019,450. In this patent, Epson makes claims relating to a method of determining the ink level through the measurement of electrical resistance between electrodes within the cartridge and a comparison of that to a resistance table stored on a chip. There is nothing in this patent about storing the resistance actually measured. One can remove and then replace the cartridge without such memory, since the resistance is measured repeatedly by the printer. The chip may therefor be only a place for storing the lookup table and some program code to make use of the data and refilling the cartridge will automatically restore it's functionality. The only thing refillers would then need to be concerned with relative to this function is the electrical resistance of their ink as compared to the original epson ink. The patent also makes claims for the closeable ports and a few other items that will make our lives better, or at least less messy. I should note that I have not read all the patents received by Epson so there may be still another one that does describe a method of preventing refills. There are two such patents assigned to a German company that involve the automatic physical destruction of the cartridge. Also, Brother has a patent that uses methods similar to the Epson patent to detect ink levels and it does record to a chip. Finally, for now, I found it interesting that there are a number of patents related to refilling cartridges that are assigned to HP. Seth - Please turn off HTML mail features. Keep quoted material short. Use accurate subject lines. http://www.leben.com/lists for instructions.