The ST range grew from a number of elements in 1985, such as a separate PSU and disk drive, to an integrated unit launched as the 520STFM.

Designations in the ST range include "F" for an integrated FDD, "M" for a built-in TV Modulator and "E" for the Enhanced or Extended line.  Memory started out with a small allocation of 128Kb for the 130ST, this was never released, and the 260ST (256Kb) saw only a limited production run.  The ST launched with 512Kb of internal RAM (520ST), and some European models also had the designation "520ST+", which was a standard 520ST with another 512Kb "piggybacked" onto the existing memory.

Soon, a 1MB machine was launched, and the Atari 1040ST was the first computer in the world to offer a full 1MB RAM for under $1000.00.

A more professional ST was launched called the MEGA ST, this had a detachable keyboard, and the first ST to offer 2MB and 4MB of RAM.  See the Mega ST section for more information.

Atari launched the STE line in 1989, and it was designed to compete with Commodore Amiga 500.  Although Atari denied this claim, the STE was an upgrade to combat the weaknesses perceived by the press of the existing model.  These were namely internal sound, colour and hardware scrolling abilities, which were squarely aimed at the games publishers.  unfortunately, most games publishers rarely used the new specifications of the STE due to the additional work, and to ensure compatibility with older STFM models.

Atari always denied that the STE was rushed out the door, but problems with the DMA chip, which led to Hard Drive errors, and the problems with the upgraded GEM/TOS OS, led observers to believe that this was the case.  Eventually, these problems were rectified, but the damage was done, and the journalists didn't do the company any favours.

The STE did have some unique and clever features, including the first home computer to offer easy memory upgrades by utilising slot-in memory modules (although the case still had to be opened using a screw-driver!).  Atari also added 2 additional joystick ports, which were advanced digital controller ports, another first.

The last ST designed by Atari was the Mega STE.  Visit the Mega STE section for more information.