This invention relates to methods for increasing the speed of computer system and particularly for increasing the speed of execution of computer programs. When a computer program is to be executed, a single command is loaded from a random access memory (RAM) into an instruction register (IR) (or program counter) and a number of clock pulses are applied to that register. The clock pulses move that command, referred to as a "word", through the IR to a processing unit. From the processing unit the word goes to an arithmetic/logic unit (ALU) and then back to the processing unit. The ALU performs one or more operations upon the word. The word then moves from the processing unit to the memory subsystem and from the memory subsystem to the processing unit, depending upon the type of instruction which is in the word. At the end of the instruction, the word is moved back to the RAM for execution in a succeeding cycle. In order to facilitate the movement of the word through the processing units and memory subsystem, the various components of the computer may be interconnected by means of a high speed communication system, such as a bus. The bus provides a direct link between each of the components and may include, for example, a 64 bit wide data bus. Typically, bus data rates are in the order of 4.times.10.sup.9 bits per second or 4 gigabits/sec. With a large machine, there may be more than one bus and the components may include processors, main memory, high speed input/output units and other subsystems, such as disk storage devices and tape drives. In the latter case, the tape drive and the main memory (usually RAM) will be closely coupled. The system of bus and the connected components may provide a complex communication system. In general, as the speed of execution of programs increases, the execution time may decrease. The speed of a computer is determined by the bus which has a bandwidth which is defined as the number of bits per second which may be transmitted by the bus. The bus bandwidth is, in turn, dependent upon the clock frequency used to drive the bus. The clock frequency may be expressed in hertz (Hz). In large machines, a clock, such as a digital frequency synthesizer, may be used to generate a number of output signals which are supplied to a bus driver. Each of the output signals have different frequencies so that the clock will have, at its output terminals, a number of signals which are non-harmonic. In other words, if two signals are derived from the clock, their frequencies are not harmonics or integer multiples of each other. It is to be understood that such a clock is not a conventional clock. The use of such a clock is advantageous in a computer system where a plurality of processors and subsystems communicate with each other. Since the clock generates signals which are different in frequency, the signal used for each communications channel can have its own frequency which is separate from, and not harmonically related to, any of the other signal frequencies used for that computer. In this manner, the signals can be supplied to a multiplexer which selects different ones of the signals for different of the buses in the computer system. The clock may supply a series of non-harmonic signals to a bus. Thus, in a conventional computer, a communications system as discussed above may be used to supply a number of signals to a number of buses which have different non-harmonic frequencies. The choice of the signal frequencies is dependent upon the selection of signals for the buses to be used. In this way, the communication channels are separated so that communications over any of the channels cannot interfere with communications over another channel. While, as noted above, a frequency synthesizer may be used to supply non-harmonic clock signals to a bus, other mechanisms may be used for such signals. In particular, signals may be generated by a counter which may be driven by a programmable non-harmonic signal. The choice of the non-harmonic frequency is, in part, determined by a frequency which is supplied to the bus by the communications system. The communications system may, for example, use an external computer, such as a personal computer, or an internal bus of a processor or a master subsystem. In either case, the frequency which is supplied to the bus is determined by the communications system. It may be that the frequency is generated by a counter which counts at a frequency which is supplied by a fixed clock source such as a crystal oscillator. When the communications system is connected to a processor, such as a Pentium II microprocessor manufactured by the Intel Corporation, the frequency is determined by the control program which controls a programmable frequency clock generator of the microprocessor. In such a case, the frequency may be different each time the program is executed. In order to supply a signal to a bus, it may be necessary to synchronize the clock with the data on the bus. It may also be necessary to synchronize the frequency of the clock with the clock frequency of the bus so that the data received by the bus is sampled properly. As noted above, the communications system is used to supply a non-harmonic signal to a bus. In some systems, a harmonic signal may be used in conjunction with the non-harmonic signals for supplying data to and receiving data from the bus. However, the use of a harmonic clock may result in problems. A harmonic clock may introduce distortion into signals which are carried by the bus. This may be particularly a problem where a series of signals are being transmitted on a bus which carry data at a high rate of speed. With harmonic clocks, a single frequency harmonic is produced by the bus each time a clock period begins and ends. Such harmonics may affect the signals carried by the bus. It is, therefore, desirable to provide a new method for generating a high frequency clock which avoids harmonics and which permits a series of signals of different frequencies to be generated. It is also desirable to provide such a method which uses non-harmonic signals for supplying clock signals to a bus.