This was the first computer to be equipped with a fully bit-mapped colour GUI. In 1986 Atari upgraded the basic design with the 1040STF, which was similar to the early 520ST, with the power supply and double-sided floppy drive now in the back of the housing of the computer instead of being external. This made the computer bigger but reduced the amount of cable at the back, and the same design was also used for the new 512 KB 520STFM, which replaced the earlier models. The early STF machines lacked the 'M' modulator that allowed a TV to be used. The STF machines would only work with a monitor. In 1989, Atari released the STE, similar to the ST but with improvements to the multimedia hardware and operating system. The STE featured an increased colour palette of 4096 colours from the ST's 512. Atari stopped producing ST computers in 1993.