careful attention to timing to modify the attribute area of RAM at certain specific times as the display was drawn - let the display hardware draw one line of the display, then change the attribute RAM before the next line is drawn to give the effect of different attributes for each individual line. These changes had to be done in software and were time-consuming to program, meaning that this technique was usually limited to special effects. This technique was also very popular in the demoscene. The problem and solutions Most games before 1987 ignored attribute clash. Some later games, such as Knight Tyme and Three Weeks in Paradise allowed players to select between two modes of attribute clash: one which ignored main character attributes, blending the character into the background and vice versa, prioritising the characters colour scheme over the background imagery. Another workaround was to simply render the graphics in two colours, otherwise known as monochrome, as done with the Spectrum version of Knight Lore in 1984. Many games used full-colour backgrounds and "character scrolling" (where the environment was scrolled eight pixels at a time), but monochrome sprites that were effectively transparent, as in Double Dragon, were drawn in such a way so they stand out, avoiding dependence on colour. Many games used this method with smooth pixel-by-pixel scrolling, but the attribute clash as elements of one character block were "passed" to the next were clearly visible. A prominent (and less successful) example of the use of full-colour graphics was the Spectrum conversion of Altered Beast. The game suffers from considerable attribute clash. Programmer Don Priestley developed a distinctive style for several of his games by using large, cartoon-like sprites which were carefully designed to span whole character blocks without appearing unduly square. A disadvantage of this technique was that the gameplay had to be designed around the graphics, and so it was not useful for ports from other platforms. Games that used this technique included Popeye, The Trap Door, Through the Trapdoor, and Flunky. Other developers who used a similar technique included Mike Singleton, with Dark Sceptre, and Gang of Five, with Dan Dare: Pilot of the Future. In 1994, programmer Igor Maznitsa developed a multi-CPU concept platform "ZX-Poly" based on ZX-Spectrum-128; the platform allows for avoidance of attribute clash, and can even colourise many old games without changes in executable code. References Sources of the ZX-Poly emulator