Atari ST: Encyclopedia - Atari ST

Atari ST

The Atari ST is a home/personal computer that was commercially popular from 1985 to the early 1990s. It was released by Atari in 1985. The "ST" allegedly stood for "Sixteen/Thirty-two", which referred to the Motorola 68000's 16-bit external bus and 32-bit internals.

Atari ST - Overview

The Atari ST was a notable home computer, based on the Motorola 68000 CPU, with 512 KB of RAM or more, and 3½" floppy disks as storage. It was similar to other contemporary machines which used the Motorola 68000, the Apple Macintosh and the Commodore Amiga. Although the Macintosh was the first widely available computer with a graphical user interface (GUI), it was however limited to a monochromatic display. The Atari ST was notable, being the first computer with a fully bit-mapped color GUI. It had an innovative single-chip graphics subsystem (designed by Shiraz Shivji) which shared the full amount of system memory, in alternating clock cycles, with the processor, similar to the earlier BBC Micro and the Unified Memory systems that have become common today. It was also the first home computer with integral MIDI support.

The ST was primarily a competitor to the Commodore Amiga systems. This platform rivalry was often reflected by the owners and was most prominent in the Demo Scene. Where the Amiga had custom hardware which gave it the edge in the games and videowork market, the ST was generally cheaper and slightly faster at basic operation. Thanks to its built-in MIDI ports it enjoyed success as a music sequencer and controller of musical instruments among amateurs and professionals alike, being used in concert by bands such as Tangerine Dream. In some markets, particularly Germany, the machine gained a strong foothold as a small business machine for CAD and Desktop publishing work.

The ST was later superseded by the Atari TT and Falcon computers, and ST technology was used in the creation of the Atari Jaguar video game console.

Since Atari pulled out of the computer market there has been a market for powerful TOS-based machines (clones). Like most "retro" computers the Atari enjoys support in the emulator scene.

Atari ST - Origins

Atari had created two released machines in the form of the Atari 2600 console (also known as VCS) and the various Atari 8-bit based home computers. Both of these lines were created around the 6502 CPU and included a number of additional chips assisting this rather basic, but cost-effective CPU in providing graphics and sound. In fact the 8-bit machines had originally intended to be the replacement for the 2600, but they were later reengineered as home computers.

As Atari grew and the management was shuffled by Warner (their parent company), the creators of the 2600 and 8-bit machines eventually got fed up and left. A group of them led by Jay Miner formed a small think tank called Amiga in 1982 and set about creating the third generation machine, this time based on the much more powerful 68000 CPU.

During this time, the home computer market started to slow down, and the video game market underwent the great video game crash of 1983. Warner management decided to "get out" and started looking to sell Atari outright. Meanwhile many of the same effects were in the process of decimating Commodore International. An argument involving Commodore's chairman and largest shareholder Irving Gould, and Jack Tramiel ensued over development of a new 68000 system, resulting in Tramiel's immediate departure from Commodore in January of 1984.

Tramiel immediately formed a holding company, Tramiel Technology, and brought in a number of ex-Commodore staff to continue his project to develop a new, high-performance home computer. While this team, led by Shiraz Shivji, worked on the design, Tramiel discovered that Warner Communications wanted to sell Atari Corp. Tramiel purchased Atari Corp, mainly for the overseas manufacturing and dealer network. The design team considered "one-upping" the Macintosh by using a full 32-bit chip, namely the NS32032, but in talks, National Semiconductor couldn't supply the numbers, or price, the project needed. In retrospect this proved to be lucky, a prototype built on the NS32032 proved to be slower than the 16-bit 68000.

The basic hardware design quickly "gelled" into a form that was almost identical to the ST that eventually shipped. The design used off-the-shelf parts where possible. Disk drive support was provided by the WD1772, a standard Western Digital chip, and sound from a Yamaha YM2149, a clone of the common but fairly basic General Instruments AY-3-8910. Serial, MIDI, and other I/O functions were provided by standard Motorola chips. The custom chips included a memory controller, the simple "Shifter" graphics chip, a DMA controller, and the "GLUE" interrupt handler.

At about the same time, Amiga were desperate for a buyer or investor, and the "Warner owned" Atari had paid Amiga for development work (see: "TOP SECRET: Confidential Atari-Amiga Agreement"). In return Atari was to get one-year exclusive use of the design. Atari was also working on a "high-end" 68000 based machine at the time, so it is not clear what their intentions for the Amiga design were.

By May Tramiel had secured his funding, bought the remains of Atari from Warner for a very low price, and set about re-creating his empire. One of his first acts was to fire practically all of Atari's highly respected engineering staff, and cancel almost all ongoing development. The Amiga crew was upset, and soon entered discussions with Commodore that led to them purchasing Amiga, and quickly cancelling Atari's license. Tramiel was furious, and the resulting court case lasted for years. Finally, it settled out of court, the details of which remain secret.

Work thus continued with the design started at Tramiel Technology. With the basic design complete, the team started looking at solutions for the operating system. Soon after the buyout Microsoft approached Tramiel with the suggestion that they port Windows to the platform, but the delivery date was out about two years, far too long for their needs. Another possibility was Digital Research, who were working on a new GUI-based system then known as Crystal, soon to become GEM. A final possibility was to write a new system in-house, but this was eventually rejected due to risk.

DR seemed generally uninterested in porting the system themselves, so a team from Atari was sent to their Monterey headquarters to do it themselves. They were given the latest versions of the Intel 8086 code from their DR counterparts, and would port it to the 68000 as quickly as possible. A version, running on top of CP/M-68K, was available just in time for the January 1985 CES, where the ST was introduced.

CP/M-68K was essentially a direct port of CP/M's original, and very old, operating system. By 'modern' standards of 1985, it was rather outdated both in terms of command structure, and that it didn't support hierarchical file systems. DR was also in the process of building a new DOS-like operating system specifically for GEM, GEMDOS, and there was some discussion of whether or not a port of GEMDOS could be complete in time for product delivery in June. The decision was eventually taken to port it, resulting in a GEM/GEMDOS system Atari referred to as TOS. This was beneficial to the system, as it allowed the ST to read and write standard IBM PC disks.

The design shipped in June 1985 as the 520ST. The machine had gone from concept to store shelves in a little under a year. Atari had originally intended to release versions with 128 KB and 256 KB of RAM as the 130ST and 260ST respectively, but the rapidly falling prices of RAM at the time led them to cancel these versions and it was released with 512 KB only. In 1986 the 1040ST^F (also written STF) shipped with 1 MiB of RAM and featured an integral power supply and double sided floppy-disk drive. The 1040ST was the first personal computer shipped with a base RAM configuration of 1 MB, and when the list price was reduced to $999 in the U.S. it became the first computer to break the $1000/MB price barrier. However, the ST remained generally the same internally over the majority of its several-year lifespan. The choice of model numbers was inherited from the model-numbers of the XE series of the Atari 8-bit family of computers.

Atari ST - Description

The 520ST was an all-in-one unit, similar to earlier home computers like the Commodore 64. However, by this time the market demanded a "full sized" keyboard, including cursor keys and a numeric keypad. For this reason the 520ST was fairly "boxy", generally oversized for a machine that one had to move around to adjust the keyboard position. Adding to this problem was the number of large cables needed to connect to the peripherals. This problem was addressed to some degree in the follow-on models which included a built-in floppy disk.

Following most machines of the era, and thus differing greatly from earlier Atari designs, the ST used a large number of one-off ports mounted on the rear of the machine. In addition to power and monitor connections, the ST included an RS-232 serial port, a Centronics printer connection, two Atari-standard joystick/mouse ports, an ACSI (not SCSI) hard drive connector, the floppy disk connector, a cartridge port and the two MIDI ports.

The case followed the Tramiel-Atari design of the era, being basically wedge shaped, with a series of grilles cut into the rear for airflow. The original 520ST design used an external floppy drive, the 1040ST-style case featured a built-in floppy drive. The power supply for the early 520ST was a large external brick while the 1040ST's was inside the machine. In addition the majority of the machines had keyboards with a very soft tactile feedback, not as good as those on the IBM PC. The design was much improved with the Mega ST series which included a detached high-quality keyboard and stronger case, but this apparently cost too much to produce and the design was not used widely.

Atari initially used single-sided disk drives that could store up to 360 KB. Later drives were double-sided versions that stored 720 KB. Due to the early sales of so many of the single-sided drives, almost all software would ship on two single-sided disks instead of a single double-sided one, in fear of cutting off all the other owners. Another problem was that the Atari double-sided drive could read IBM formatted disks, but IBM PCs could not read Atari disks. This was a formatting issue that was later resolved by third-party software formatters and TOS upgrades.

Additionally they had originally intended to include GEM's GDOS hardware abstraction layer, which allowed programs to draw (display, print, etc.) graphics to any supported device with no changes. This allowed developers to write a program for display to the screen, and get high quality printing "for free". However GDOS was not ready at the time the ST started shipping, and while Atari promised to include it as soon as possible, it was not released until much later. This left printing support up to the developers, who had to create their own engines for every possible printer.

Similarly the custom "BLiTTER" was to be included to speed the performance of graphics operations on the screen, but this was isolated to their higher-end machines and the enchanced STE models when it was eventually released. As a result, even when the BLiTTER eventually shipped, it was ignored by game developers because it was not present on all machines. However, properly written GEM programs could use the BLiTTER seamlessly since the GEM API had always supported it.

On the plus side the ST was less expensive than most machines, including Macintosh Plus, and tended to be faster than most (external link: price comparison). Largely as a result of the price/performance factor, the ST would go on to be a fairly big seller, notably in markets where the foreign exchange rates amplified prices. For this reason the ST was most popular in Europe, especially in Germany. Also, the very crisp, 640 by 400 pixels picture of its black & white monitor made it popular for small-office applications. In fact, an Atari ST and reasonable terminal emulation software was much cheaper than a Digital VT220 terminal, which was normally needed by offices with central computers.

Atari ST - The enhanced STs

For about the first four years, nothing much had changed in the capabilities of the ST platform, except for new machines being released with greater RAM. In late 1989, Atari released the ST^E (also written STE) — a version of the ST with some improved hardware.

The STE featured an increased colour palette of 4096 colours from the ST's 512, and a new hardware Blitter. It also included a new 2-channel digital sound-chip that could play stereo samples in hardware (the Yamaha YM2149 could only be coaxed into playing samples by means of software). Two analogue joystick-ports were added (two normal joysticks could be plugged into each port with an adaptor), and the RAM was now easily upgradable via SIMMs. Despite all of this, it still ran at 8 MHz and the enhanced hardware was clearly designed to catch up with, rather than improve upon the standard hardware of the Amiga.

The STE models initially had serious operating systems conflicts resulting in many applications and games written for the ST line being unusable (sometimes, this could be solved by expanding the RAM). To make matters worse, the built in floppy disk drives could not read as many tracks on a floppy disk as the built in floppy disk drives on older models. While this was not a problem for most users, some games used the extra tracks as a crude form of copy protection and as a means of cramming more data on the disk. Furthermore, having a joystick plugged in would sometimes cause strange behaviour with a few applications (such as First Word Plus).

Very little use was made of the extra features of the STE: STE-enhanced and STE-only software was rare. Look in external links for Atari STE fanpage, there you will find what software uses special Atari STE features.

Atari went on to release the Mega STE (an STE in a grey TT case that ran at 16 MHz).

At some time during the early '90s, the development of the ST line forked. On one branch was the high-end workstation-oriented TT, and on the other was the entertainment-oriented Falcon — both of which were supposed to be ST compatible, but not compatible with each other. By then, the Atari ST platform was dying and neither of these two machines took off.

Medusa Computer Systems manufactured some 3rd-party Atari Falcon/TT-compatible machines that used 68040 and 68060 processors.

Atari ST - Future of the platform

Despite the lack of a hardware supplier and commercial software vendors, there is a small active community dedicated to keeping the ST platform alive. There have been advancements in the operating system, software emulators (for Windows, Mac & Linux), and some hardware developments. There are accelerator cards, such as the CT-60, which is an 68060 based accelerator card for the Falcon, and there is the Atari Coldfire Project, which aims at developing an Atari-clone based on the Coldfire processor.

Atari ST - Software

The ST was the first home computer with built-in MIDI ports, and there was plenty of MIDI-related software for use professionally in music studios, or by amateur enthusiasts. The popular Windows/Macintosh application Cubase originated on the Atari ST.

Music tracker software was popular on the ST, such as the TCB Tracker.

An innovative music composition program that combined the sample playing abilities of a tracker with conventional music notation (which was usually only found in MIDI software) was called Quartet.

Also popular on the ST was professional Desktop publishing software, such as Calamus; and office tools such as word processors and spreadsheets.

There were many software development tools available for the Atari ST: 68000 assemblers, Pascal and C compilers, and novelty tools such as SEUCK. The ST came bundled with a disk that contained amongst other things ST BASIC, the first BASIC for the ST. However, due to its poor quality, it was eventually replaced by other BASICs, such as GFA BASIC and STOS.

The ST was one of the leading platforms for computer games from 1986 to 1988, inclusive. Notable individuals who developed games on the ST include Peter Molyneux, Doug Bell, Jeff Minter, Jeremy San, James Hutchby, Dimitri Koveos and David Braben. The first real-time 3D role-playing computer game, Dungeon Master, was first developed and released on the ST. As an indication of the popularity of the ST as a game platform, Dungeon Master was the best-selling software ever produced for the platform. In the early 1990s the software houses gradually stopped producing ST versions of their games. See List of Atari ST games and Category:Atari ST games.

Utility software was available to drive hardware add-ons such as video digitisers. Office Productivity and graphics software was also bundled with the ST (HyperPaint II by Dimitri Koveos, HyperDraw by David Farmborough, 3D-Calc spreadsheet by Frank Schoonjans, and several others commissioned by Bob Katz, later of Electronic Arts).

There was a thriving output of public domain and shareware software which was distributed by public domain software libraries.

Atari ST - Screenshots

More screenshots can be found on the Atari ST Games page.

Atari ST - Technical specifications

Atari ST - ST/ST^F/ST^M/ST^FM

As originally released in the 520ST:

• CPU: Motorola 68000 @ 8 MHz
• RAM: 512 KB
• Display modes: 320×200 (16 colour), 640×200 (4 colour), 640×400 (mono), palette of 512 colours
• Sound: Yamaha YM2149 3-voice soundchip
• Drive: Single-sided 3½" floppy disk drive
• Ports: TV out (on FM models), MIDI in/out, RS-232, printer, monitor (RGB and mono), extra disk drive port, DMA port (ACSI port) for hard disks, joystick and mouse ports
• Operating System: TOS 1.0 (Tramiel Operating System) with the Graphical Environment Manager (GEM) GUI

Very early machines included the OS on a floppy disk, but this was quickly replaced with ROM versions of TOS 1.0 instead. The later models also used an upgraded version of TOS - 1.02 (also known as TOS 1.2). Another early addition (after about 6 months) was an RF Modulator that allowed the machine to be hooked to a colour TV when run in its low resolution mode. These models were known as the 520ST^M (or 520STM). Later F and FM models of the 520 had a built in double-sided disk drive instead of a single-sided one.

Atari ST - ST^E

As originally released in the 520ST^E:

• All of the features of the 520ST
• Drive: Double-sided 3½" floppy disk drive
• Built in RF Modulator
• Extended palette of 4,096 available colours to chose from
• BLiTTER chip
• Hardware-support for horizontal and vertical fine scrolling
• Sound: Additional National LMC 1992 sound chip with 2-channel stereo 8-bit PCM sound.
• Memory: 30-pin SIMM memory slots to upgrade to 4 MiB
• Ability to synchronise the video-timings with an external device so that a video Genlock device can be used without having to make any modifications to computer's hardware
• Additional ports: Stereo RCA jacks and two analogue joystick ports (with support for analogue devices such as paddles and light pens. Two normal digital joysticks could be plugged into each analogue port with an adaptor).
• TOS 1.06 (also known as TOS 1.6) on ROM.

Later ST^E models had TOS 1.62 that fixed some bugs in TOS 1.6.

Atari ST - Models

A number of machines were released in the ST family. Here they are, in rough chronological order after the original 520ST:

• 520ST+ - Name for early 520STs with 1 MiB of RAM, but without floppy disk
• 260ST - European name for the 520ST with 512 KB. Used after the release of the 520ST+ to differentiate the cheaper 512 KB models from the 1 MiB models
• 520ST^M - a 520ST with a built-in modulator for TV output
• 520ST^FM - a 520STM with a newly redesigned motherboard in a larger case with a built-in floppy disk drive
• 1040ST^F - a 520STFM with 1 MiB of RAM and a built-in double-sided floppy disk, but without modulator
• 1040ST^FM - a 520STFM with 1 MiB of RAM and a built-in double-sided floppy disk
• Mega ST (MEGA2, MEGA4) - 1040 with 2 or 4 MiB of RAM, respectively, in a much improved "pizza box" case with a detached keyboard. These models included the BLiTTER chip, but the OS ROM was not upgraded and the extra GEM functionality needed to be booted from disk.
• 520ST^E and 1040ST^E - a 520STFM/1040STFM with enhanced sound, the BLiTTER chip, and a 4096-color palette, in the older 1040 style all-in-one case
• Mega STE - same hardware as 1040STE except for a faster 16-MHz processor, in the TT case
• STacy - A portable (but definitely not laptop) version of the ST. Originally designed to operate on 12 standard C cell flashlight batteries for portability, when Atari finally realized how quickly the machine would use up a set of batteries (the batteries were not rechargeable), they simply glued the lid of the battery compartment shut.
• ST Book (later version portable ST)

Atari ST - Other models

• Atari TT030 — new machine based on the Motorola 68030 processor running at 32 Mhz, in yet another new case design with a detached keyboard.
• Atari Falcon 030 — another 68030 based machine like the TT, but in the 1040-style case (yet again) with further upgrades to the graphics and sound, a Motorola 56000 DSP, multitasking OS (on disk) and a LocalTalk port for networking.
• Medusa 040, Medusa 060, Hades 040, Hades 060 — 3rd-party Falcon/TT compatible machines manufactured by Medusa Computer Systems.
• Atari ABAQ, or Atari Transputer Workstation — A standalone machine containing ST hardware and up to 17 transputers capable of massively parallel operations for tasks such as ray tracing.

There were also some unreleased prototypes: Falcon 040 (external link) (based on a Motorola 68040, new case and slots), and STylus (palmtop).

See also

• List of Atari ST games
• Atari ST demos — The demoscene on the Atari ST.

Adapted from the Wikipedia article "Atari ST", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki