 By using a monochrome monitor or black and white TV (or reducing the colour settings of a colour TV), it is possible to take advantage of the differences in intensity over the Spectrum's colour range to generate a 15-shade grayscale image at 256×192 resolution.Several third-party Spectrum clones, including the Timex Sinclair machines and the Pentagon, support a screen mode in which attribute blocks are 8×1 pixels in size rather than the usual 8×8.A screen in this mode takes 12 KB RAM.