Abstract: The invention is a liquid food for supplying protein principally containing protein, seasonings, flavoring materials and water, wherein it contains 5 to 15% by weight of lactalbumin as the protein. The lactalbumin is obtained by heating to denature under conditions so as to form a cloudy solution. The food is useful for undernourished patients who suffer from hypoproteinemia, hypoalbuminemia or common healthy men who need protein so as to desire to supply nutritious food and develop their muscles.

Abstract: A computer system for preventing copying or duplication of a program which has a CPU, a ROM, a RAM, an FDD unit, a loader program executed by the CPU for loading the program from the FDD unit to the memory, an address selector switch, and an FM/MFM modulating circuit. The CPU reads the program from the FDD unit to the RAM under the control of a control program stored in the ROM, the program being stored in the FDD unit in the MFM mode which does not allow readout of the program by the loader program. The readout program is modified by the FM/MFM modulating circuit in accordance with a machine number unique to the machine and read from the address selector switch. The modified program is written in the FDD unit by the FM/MFM modulating circuit.