from either the BRIGHT or non-BRIGHT halves of the palette. Trying to add a third colour in an 8x8 pixel area would overwrite one of the previous colours. The ZX Spectrum used 6144 bytes for the bitmap, with one byte representing eight pixels, and used 768 bytes for the colour attributes. This gives a total of 6912 bytes for the entire graphics display, a relatively small total for a computer of the Spectrum's era with "colour" capabilities. This graphics architecture was retained right through to Sinclair and Amstrad's later redesigns of the Spectrum, up until Amstrad's final model, the ZX Spectrum +3, despite subsequent models having contained 128 KiB of RAM, reducing the need to save memory in this manner. The architecture was retained to prevent loss of backward compatibility. Attributes were used by a variety of other computers and consoles, including the Commodore 64, the MSX and NES, although the size of the attribute blocks and the number of colours per block varied. However, with the use of hardware sprites, attribute clash could be avoided. The Thomson MO5 and TO7 microcomputers, the Oric 1, the MSX 1 architecture, and other systems based on the Texas Instruments TMS9918 video display controller display a very similar constraint: for each group of eight pixels horizontally, only two colours out of 16 are available, giving a similar but less severe effect than with the Spectrum. The MSX 1 did not have just one single colour attribute byte available for a whole 8x8 pixel area, as was the case with the Sinclair Spectrum, but eight, with one attribute byte for each 8×1 pixel group. Thus, while the Spectrum was limited to one colour pair for a square area of 8x8 pixels, the MSX 1 was only limited to one colour pair for a "line" of eight adjacent pixels. In addition MSX1 could use sprites which were not bound to any attribute clash problems (although MSX 1 sprites did have their own limitations, such as being monochrome). In practice this technical advantage often did not help MSX 1 systems to produce better pictures. The problem for the MSX 1 was that many European software companies who converted Spectrum games to MSX 1 ignored all the improvements the MSX 1 had over the Spectrum, and thus the resulting MSX 1 versions had the same amount of attribute clash as the original Spectrum games (Jack the Nipper