 In the case of the Timex, this mode is activated through the command OUT 255,2.In addition, this screen mode can be generated through the use of the MB03+ Ultimate interface, the MB-02 disk system's DMA hardware (where the technique is known as Multitech), and is also available as Mode 2 on the SAM Coupé.On other Spectrum models, this effect can be replicated by exploiting the fact that the ULA re-reads the attribute information on every pixel row when generating the video output; it is possible to write a new value to the relevant memory location in between successive lines, and thus cause a different pair of colours to be shown.