sellerof the cable didn't say what chip but he sent a driver link: for imac you could try use this driver: http://www.prolific.com.tw/support/files/%5CIO%20Cable%5CPL-2303%5CDrivers%20-%20Generic%5CMacOS%5CMacOS%2010.x%5Cmd_PL2303_MacOSX10.6_dmg_v1.4.0.zip I guess I'll find out soon enough. thanks