revision preference src: The ZX Spectrum emulation retains the technical idiosyncrasies of the original hardware. Their graphics fluctuate in render speed depending on the number of items the computer has to process on-screen. <SEP> tgt: The ZX Spectrum emulation retains the technical idiosyncrasies of the original hardware. For instance, their graphics fluctuate in render speed depending on the number of items the computer has to process on-screen.