To introduce its new ST computer line, Atari unveiled the slogan, "Power Without the Price." The Atari ST line debuted with the 520ST, it became the most inexpensive of the 16-bit computers available.
The "ST" stood for its "Sixteen/Thirty two"-bit Motorola 68000 processor. The 520ST was officially introduced at the Las Vegas Consumer Electronics Show on January 5, 1985. At the date of launch, the 520ST came equipped with an external 3.5-inch disk drive, the STM1 mouse and a monitor (either monochrome or optional color). The ST line represented Atari's attempt to break into the 16-bit computer market.
The 520ST finally hit store shelves in the US in September 1985 when the 8-bit computer war was at its peak. From 1978 to 1984, Atari had been run by Time/Warner. Former chief of Commodore, Jack Tramiel, acquired the company in 1984 and released the 16-bit ST only a year later. The retail price for a 520ST was $799.99 for a system with a monochrome monitor and $999.99 for one with a color monitor.
When it was released, the press dubbed the 520ST the "Jackintosh" as it was the product of Atari president Jack Tramiel and because the system had the power of a Macintosh (but cost only about half as much).
The Atari ST's operating system was called the TOS, an apparent acronym, though no one was sure exactly what words its letter's signified. TOS is commonly believed to mean "The Operating System", but some have speculated, "Tramiel Operating System." When Atari originally introduced the 520ST the TOS needed to be loaded externally via a 3.5-inch floppy disk it was not contained in the ROM. TOS 1.0 was shipped with the 520ST and 1040ST computers.
Atari utilized the GEM (Graphical Environment Manager) Interface from Digital Research for the ST's graphical user interface (GUI). With such features as on-screen menus located at the top of the screen and windows, the ST's GUI bore a resemblance to the Macintosh's Mac Finder operating system.
The first two entries into the Atari ST line, the 520 and 1040, utilized the Motorola 68000 processor which ran at 8MHz.
The 520ST supported three display modes: high resolution - 640 x 400 pixels in monochrome (which was more than the Macintosh could display), medium resolution - 640 x 200, 4 colors from a palette of 512 and low resolution - 320 x 200 pixels in 16 colors from a palette of 512.
The 520ST featured a large number of interfaces including a dedicated parallel printer port, a serial modem port, Midi in and out ports, a port for an additional floppy drive, monitor output (the computer could autodetect the type of monitor being used). The 520 and 130ST both featured two joystick ports.
The ST also contained a MIDI port which made it a popular choice of musicians who utilized the computer as a MIDI sequencer. With its built-in MIDI interface the ST line became very popular with musicians.
In its seven years on the market, the 520ST sold more than 1.5 million units around the world. The system was a especially a success in Europe where it received superior support.
The 520 was then followed by the 1040ST. It came with 1024KB of memory as well as a built-in 800KB floppy disk drive. The 1040 retailed for $999 (with a monochrome monitor) comapred to other 16-bit systems of the time like the Apple Macintosh Plus at $2195, Commodore Amiga at $1795 and the IBM at $4675.
Following the 1040 was the Mega ST which Atari introduced in January 1987. The Mega ST came with a detachable keyboard, a standard double sided 3.5" disk drive. 1 or 4 megabytes of RAM and a 20 megabyte hard drive. The Mega ST was aimed at the desktop publishing market and was priced at less than $3000 (with printer).
Later in the ST line were the STacy and the STBook - both laptop computers. The Atari TT, also known as the "Super ST" was an attempt by the company to break into the business computer field.
In 1987, Commodore announced the release of the Amiga A500, which gradually ate into the business Atari was doing with the ST line. Several classic games were designed for the ST. They came from such companies as Bitmap Brothers, Bullfrog, Core Design and Llamasoft. ~ Dave Beuscher, All Game Guide