A method of waveform drawing, including generating a plurality of waveforms with certain waveforms being in the same space in a display, eclipsing the waveforms in a rank order and storing the related data in an eclipsed list, the related data of the eclipsed list including a plurality of drawing points with the results of eclipsing the waveforms in the rank order, performing a reduction of flicker on a displayed image from the data outputted from the eclipsing of the waveforms in rank order, an erasure list and a draw list including the results of the reduction of flicker, optimizing the erasure list from the data outputted from performing the reduction of flicker and storing in an optimized erasure list, and copying from the eclipsed list to a predecessor list, the predecessor list including drawing units representing vertical stripes at a given x-axis position.