1 8 mhz to 40 khz the use of iref as a 5 khz source of the serially shifted waveform bit pattern remains unchanged the slower shift rate produces a shorter bit pattern to represent the 5 khz iref in particular the bit pattern will be four bits set followed by four bits cleared the shorter bit pattern produces correspondingly shorter moving electro static square waves on the platen whereas in the case of coarse measurement one wavelength exceeded the maximum length of the platen the wavelength of a fine wave is considerably shorter than the platen that is there will be several cycles of fine waves on the platen and any of several cursor positions i e at intervals of one fine wavelength will produce the same result in the phase counter this does not cause a problem and results in an overall increase in the resolution of the x coordinate the multiplicity is resolved as follows the coarse measurement can be examined to determine which of the fine cycles contains the cursor location then the coarse measurement can be converted to an equivalent integral number of fine cycles which is then augmented by the fine measurement the procedure outlined for x dimension measurement is analogous to the one used for measurement in the y dimension here is how the two activities are coordinated the series of x measurements is performed first to do this both the x and y shift registers are first cleared then the x shift register is allowed to begin shifting at the coarse rate the y shift.