The present invention provides a method and system that uses serial, writable, nonvolatile memory (serial memory) in a portable radio telephone. According to an object of the present invention, the serial memory may be integral to a cell phone or attached to a cell phone via an add-on card or the like. According to another object, the serial memory may be embedded in a cell phone accessory or attached to an accessory via an add-on card or the like. In both objects, once the portable radio telephone is powered on, data stored in serial memory is transferred into onboard random access memory (RAM), which in turn is utilized by the CPU and/or other cell phone systems. Serial memory includes, but is not limited to, NAND-type flash memory, as well as, flash and EEPROM memories that utilize the following interface architectures: the mircowire bus, the I²C bus, the SPI bus and/or the MPS bus. Among other things, serial memory may store the operating system, applications, and radio calibration parameters.