--- title: Atari 520 ST / ST+ / STM categories: - Computers types: - Home Computer origins: - U.S.A. years: - '1985' cpus: - Motorola MC68000 params: name: 520 ST / ST+ / STM image: /media/museum/photos/atari_520st_system_1.jpg company: /companies/atari company_name: Atari specs: - label: NAME value: 520 ST / ST+ / STM - label: MANUFACTURER value: Atari - label: TYPE value: Home Computer - label: ORIGIN value: U.S.A. - label: YEAR value: '1985' - label: KEYBOARD value: Full-stroke keyboard with numeric and editing keypads - label: CPU value: Motorola MC68000 - label: SPEED value: 8 mHz - label: CO-PROCESSOR value: '''Shifter'' and ''Glue'' custom chips' - label: RAM value: 512 KB (520 ST/STM), 1 MB (520 ST+) - label: ROM value: 192 KB - label: TEXT MODES value: 40 or 80 columns x 25 lines - label: GRAPHIC MODES value: 320 x 200 / 640 x 200 / 640 x 400 dots - label: COLORS value: 16 among 512 (320 x 200) / 4 among 512 (640 x 200) / monochrome (640 x 400) this last mode needs a special monitor. - label: SOUND value: 3 voices, 8 octaves - label: SIZE / WEIGHT value: 47 (W) x 24 (D) x 6 (H) cm - label: I/O PORTS value: RGB, TV modulator (520STm), Cardridge, Midi (in/out), Centronics, RS232c, Hard Disk, Floppy Disk, Joystick, Mouse - label: BUILT IN MEDIA value: External 3.5'' 360 KB disk-drive (option) - label: OS value: TOS / GEM - label: POWER SUPPLY value: External power supply unit - label: PRICE value: £749 (1985, UK), £399 (1986, UK) tabs: - photos - adverts - hardware - emulators - links - docs photos: - title: ATARI 520 ST subtitle: '' text: it has the same characteristics as the 130 ST and the 260 ST, save for its added memory image: /media/museum/photos/520st.jpg - title: 520 ST MOTHERBOARD subtitle: '' text: |- **(1)** SHIFTER custom circuit. Woks with the MMU to produce the video signal\ **(2)** 512 KB RAM memory chips (256K x 1 bit)\ **(3)** 2 x 6850 ACIA's. Manage asynchronous communications with keyboard, mouse, joysticks (first) and MIDI interface (second)\ **(4)** YM-2149 sound generator chip (3 tones generator + noise generator)\ **(5)** MMU custom circuit. Manages RAM address bus and video signal with the SHIFTER\ **(6)** Motorola 68000 microprocessor\ **(7)** GLUE custom chip. Manages the entire system and data transfer between various chips.\ **(8)** Western Digital 1772 floppy disk controller chip.\ **(9)** Multi-Function Peripheral 68901 chip. Performs a 8-bit parallel port, a built-in serial interface, timers and interrupts.\ **(10)** DMA controller chip. Oversees data transfer from F.D. and H.D. drives and various peripherals\ **(11)** 6 x ROM chips holding the BIOS and GEM operating system\ **(12)** ROM cartridge connector\ **(13)** Hard-disk unit DB19 connector\ **(14)** Floppy-disc unit 15-pin DIN plug\ **(15)** Modem/Serial DB25 connector\ **(16)** Printer/Parallel DB25 connector\ **(17)** RGB monitor DIN plug\ **(18)** RF modulator and TV output chinch plug\ **(19)** Musical interface MIDI in\ **(20)** MIDI out\ **(21)** Power DIN plug. Power is supplied by an external power supply unit\ **(22)** Power On/Off switch\ **(23)** System Reset switch\ **(24)** 2 x joystick plugs **Ari Feldman** specifies:\ The "Shifter" and "Glue" chips were not coprocessors in the traditional sense. The base ST models had four custom chips:\ \* Shifter - Video\ \* DMA - DMA and bus access\ \* MMU - Memory access\ \* Glue - "glues" the operation of the other three chips together\ Noe of these four chips could work independently. They were designed for very limited and specific functions and designed to only work with each other. For example, the Shifter woun't work without the MMU, etc.\ Coprocessors wouldn't be added to the ST line until 1987/88 when the BLITTER chip arrived, which was basically a hardware implementation of the ST's RasterOps routines. image: /media/museum/photos/atari_520_motherboard_1.jpg - title: REAR CONNECTORS subtitle: '' text: |- **(1)** 2 x joysticks connectors\ **(2)** Reset switch\ **(3)** Power On/Off switch\ **(4)** Power supply DIN plug\ **(5)** MIDI out\ **(6)** MIDI in\ **(7)** TV RF output\ **(8)** RGB video DIN plug\ **(9)** Printer DB25 connector\ **(10)** Modem DB25 connector\ **(11)** Floppy-disc unit plug\ **(12)** Hard-disk unit DB15 connector image: /media/museum/photos/atari_520st_back_1.jpg adverts: - title: UK ADVERT subtitle: '' text: |- One of the first advert for the Atari 520ST checked against an Apple Mac and an Apricot computer. Thanks to **Bradley Sturch** image: /media/museum/pubs/atari_520st_pub_s2.jpg hardware: - title: SF-354 subtitle: Single density disk-drive text: '' image: /media/museum/hardware/atari_st_sf354-diskdrive_1.jpg - title: SF-314 subtitle: Disk-drive text: '' image: /media/museum/hardware/atari_st-disk-drive_sf314.jpg - title: CUMANA DRIVE subtitle: '' text: '' image: /media/museum/hardware/atari_520_cumanadrive_1.jpg - title: SUPRADRIVE subtitle: 20 Mb hard-disk text: '' image: /media/museum/hardware/atari_supradrive_20mb.jpg - title: 170MB QUANTUM HARD-DRIVE subtitle: '' text: This unit has an ICD Host Adapter. image: /media/museum/hardware/atari_st_quamtum_hd170.jpg - title: ATARI MEGAFILE 30 subtitle: '' text: This hard-drive has a 30Mb capacity. image: /media/museum/hardware/atari_st_megafile30_1.jpg - title: INSIDE THE MEGAFILE 30 subtitle: '' text: |- **(1)** Seagate MFM 30 MB hard-disk Type ST-238\ **(2)** Power supply\ **(3)** Logical board\ **(4)** Power and disk access LED's image: /media/museum/hardware/atari_megast_insidemegafile_1.jpg - title: MEMORY EXPANSION subtitle: '' text: 512 KB to 2 MB memory expansion, depending of the memory chips used. image: /media/museum/hardware/atari_520st_memexp_1.jpg - title: ATARI UNIVERSAL MODEM subtitle: '' text: |- The SX212 modem was one of the rare Atari peripherals that could be used with all the Atari computers range, from the 400/800 series up to the Falcon. It had both the Atari I/O ports for the 8-bit systems and a standard RS-232 connector for ST's It was a 300/1200 baud modem compatible with the well-known Hayes 'AT' commands.\ Cable and software was sold separately, depending of the computer used. image: /media/museum/hardware/atari_520_modemsx212_1.jpg - title: SML-804 subtitle: Laser printer text: |- The SLM-804 was actually a Kyocera F1000 printer but without neither on-board processor and memory nor buttons other than the on/off switch. It was first delivered with the Mega ST but could be connected on all of the ST series computers through a dedicated interface box.\ The printer used the processing power and the RAM memory of the ST computer for printing at 8 pages per minute and 300 DPI. The paper tray held 250 sheets. Thanks to **Francois Michaud** who donated us this printer. image: /media/museum/hardware/atari_megast_slm804printer_s1.jpg - title: SMLC-804 subtitle: Laser printer interface text: This interface allowed the SML-804 printer to be connected to any Atari ST holding at least 1 MB RAM. image: /media/museum/hardware/atari_megast_slmcinterface_s1.jpg emulators: - title: Pacifist ! url: http://www.pacifist.fatal-design.com/ platform: MS DOS text: Pretty good emulator - title: Gemulator url: http://www.emulators.com/gemul8r.htm platform: Windows text: '' - title: MagiCPC url: http://www.application-systems.de/magicpc/index.html platform: Windows text: '' - title: SainT url: http://saint.atari.org platform: Windows text: The best Atari ST Emulator ! - title: Steem url: http://steem.atari.st/ platform: Windows text: Excellent emulator for 1040/520 STE ! - title: Tos2Win url: http://www.aixit.com/tos2win/ platform: Windows text: A good Atari GEM Emulator ! - title: MagiCMac url: http://www.application-systems.de/magicmac/index.html platform: Apple text: '' - title: NoSTalgia & PowerST url: http://users.skynet.be/sky39147/ platform: Apple text: '' - title: STonX Homepage url: http://www.complang.tuwien.ac.at/nino/stonx.html platform: Unix / Linux text: '' - title: Atari ST Emulator url: http://www.atari-st.lovely.net/ platform: Other platform text: Written in Java ! - title: ARAnyM url: HTTP://ARANYM.ATARI.ORG platform: Multiplatform text: Multiplatform project - title: Hatari url: http://hatari.sourceforge.net/ platform: Multiplatform text: Hatari is an Atari ST emulator for Linux, BSD, BeOS, Mac OS X and other systems that are supported by the SDL library. More precisely, Hatari is an adaption of the WinSTon source code to the SDL library. links: - title: Atari & Commodore Home Computer Museum url: http://www.best.com/~hmk/ text: '' - title: Atari Music Network url: http://www.atarimusic.net/ text: Atari Music Network welcomes and celebrates all vintage digital musicians no matter what their computer - title: Atari ST Demo History url: http://wwwbrauer.in.tum.de/~brandtf/ataridemos.html text: '' - title: Atari ST Download Area url: http://www.chebucto.ns.ca/Services/PDA/atari.shtml text: Atari 400/800/XL/XE & ST/TT/Falcon Software download page - title: ATARI.ORG url: http://www.atari.org/ text: Looking for something on any Atari machine ? Follow the links ! - title: Dead Hackers Society url: http://www.dhs.nu/ text: Atari demo scene - title: Little Green Desktop url: http://www.atari.st/ text: Largest Atari ST ressource! - title: Medusa computer url: http://www.kingx.com/kingx/medusa/thes.html text: You can still buy an Atari ST family clone computer - title: MiNTOS Distribution url: http://www.earth.ox.ac.uk/~steve/mintos.html text: '' - title: Musique.Atari.Org url: HTTP://MUSIQUE.ATARI.ORG text: Web site dedicated to the ATARI and the Music... - title: PLOPBOX - Atari music archive and jukebox url: http://www.plopbox.net/ text: listen to atari tunes directly from your browser - title: Polish Atari Wikipedia url: http://atariki.krap.pl text: A lot of info about Atari (in polish) - title: ST Anwender Bern url: http://my.blackpoint.ch/stab/ text: Atari ST Usergroup Bern (Swiss) - title: The Atari Historical Society url: http://www.atarimuseum.com/ text: The complete history of Atari Arcade and Home games and computers. Complete site with pictures, commercials (streaming), and full text articles. Amazing site ! - title: The Atari ST Quick FAQ url: http://www.megacom.net/~q-funk/ST/ text: '' - title: The Atari WebRing Homepage url: http://b.webring.com/hub?ring=atari text: Useful ! - title: The Ultimate ATARI Resource url: http://www.atari.org text: '' - title: What is TOS url: http://www.vanc.igs.net/~roughley/tos_main.htm text: '' - title: Index of -~archive-atari- url: http://www.umich.edu/~archive/atari/ text: '' - title: Web Wiz CAPTCHA url: http://www.webwizcaptcha.com text: French forum docs: - title: ATARI 520 ST OWNER'S MANUAL url: http://www.classiccmp.org/dunfield/atarist/index.htm cover: /media/museum/docs/couvs/atari_520st_user_doc.jpg text: |- [**ATARI 520 ST OWNER'S MANUAL**](http://www.classiccmp.org/dunfield/atarist/index.htm)written by Atari  compiled/archived by Daves Old Computers\  type of document : PDF\  size : 5 Mb\  source : [Daves Old Computers](http://www.classiccmp.org/dunfield) **... READ THE ONLINE VERSION BY CLICKING BELOW :** comments: - author: dave (uk) date: Tuesday 7th May 2013 text: i played first my 520 st later 520ste and then my 1040 which im sure had more ram. i played for hours and hours and hours i used to play Overdrive, and lots arcade games. i love the football player manager and kick off. later i got a pc and it was rubish compared to the atari, atari had major competition with amiga. me and my friends used to compare our atari v amiga and argue for hours on whose was best. - author: Jim (Canada) date: Sunday 26th August 2012 text: |- I read Enrique''s comment about an ST outrunning a PC in number crunching apps. It reminded me of a time around 1991 when I had a graphic resembling an early screensaver running on an ST. A friend came over and seemed amazed at the speed of the travelling multi-coloured trailing lines moving around the screen. He said something to the effect that his PC couldn''t do that. What amused me was the fact that the program had been written in Basic, a relatively slow running language. - author: Ed Daly (Washington, DC) date: Wednesday 27th June 2012 text: |- Army privates could buy them out of the PX for $721.00\ There was a lot of great games that could be played on this machine, one that comes with most computers today is the standard chess master called chessmaster 2000 back then. - author: Enrique Ganem-Corevera (Mexico) date: Monday 12th March 2012 text: I have fond memories of this machine. It was fast, simple, elegant and incredibly powerful (I could outrun a far costlier pc in number-crushing apps). All atari computers had great graphics (the best for their times). I once compared the same games (like some ot the ULTIMA series) on PC, MAC and others, and the winner was the ST hands down. I frequently use an emulator to use my old software, and I still have my old ST, still in working condition, with a 20 MB external hard disk. - author: derbs (UK) date: Friday 3rd February 2012 text: Never owned one of these, but thought they were the business back in the day. I had an Atari 800 and looked upon the ST with envy. Just look at those 45 degree function keys, mirroring the vents and badge. That was some industrial design ahead of its time - author: Simon Lyne (United Kingdom) date: Sunday 1st May 2011 text: |- http://www.classiccmp.org/dunfield/atarist/st520.pdf The manual for the Atari 520ST - author: Bill (Williamsport/Pa) date: Sunday 14th November 2010 text: Bill(USA/Phila.Pa) Have a 520ST in original boxes and all manuals etc. If you come get it, its yours. Don''t want to throw it in dumpster. - author: Ugo Capeto date: Thursday 4th November 2010 text: For budding musicians, it was kinda like the holy grail of computers since it was the first to have a MIDI port. It was big deal back then. - author: Bill (USA/Phila. Pa.) date: Tuesday 2nd November 2010 text: I woulod like to buy a working 520 or 1040 st. Contact me with price and condition. - author: Curtis Nielsen (USA) date: Monday 1st November 2010 text: I have a complete Atari in the box taking up space in my garage. Any market for them? - author: Fred (Cupertino, CA) date: Friday 27th August 2010 text: Great machine, and my first music sequencer. There is nothing like dividing ticks in Dr. T''s music sequencing software. :-) Dungeon Master, and Sun Dog are still two of the greatest games I''ve ever played. I never did get that Macintosh Emulator, though. - author: chris (U.K.) date: Saturday 23rd January 2010 text: I have a couple of these machines and run R/c Aerochopper-brilliant! For its time, it provides great entertainment, $ requires considerable concentration,especially hitting the target-any idea as to the Value of these machines-I have original manual $ packing box ? - author: Jorge (Chile) date: Thursday 18th August 2005 text: |- This was my first computer !\ best atari ever . =D - author: Nigel (New Zealand) date: Tuesday 27th April 2004 text: |- I remember heaps of these coming in for repair because they kept crashing or simply died. The vast majority of the crashes were caused by the ill-fitting tin-plate shielding that covered both side of the board. The pressed tin would distort and catch tracks on the PCB and cause the machine to crash. The cure was to put masking or insulation tape between the edges of the shielding and the PCB, but this wasn't entirely successful, and discarding the shielding had little adverse effect. Other crash causes were poor connections on the cpu IC. Removing it and cleaning the tarnished pins usually sorted things out, unless you didn't use the proper IC extraction tool, in which case the socket cracked and caused even more grief.\ The dead machines were usually failures of the switched-mode PSU, which was generally very difficult to repair. Failing to replace rectifiers with exactly the correct type would result in most of the electrolytics exploding. One of the Atari distributors in the UK used to offered a PSU exchange programme - send a faulty one in and get a repaired one back. - author: John Ad.Tzoyas (U.K.) date: Tuesday 24th February 2004 text: |- Had one of these machines years ago.\ In the UK they were always seen as the poor mans Amiga. What stands out in my memory was the fantastic graphic and sounds demos you could get on public domain for it.The 16bit 'wars' which surounded both this machine and the Amiga were something else! We all aspired to a 32bit Archimides though. - author: Mike (U.K.) date: Saturday 2nd August 2003 text: This machine really set a new standard in the music recording arena as it was the only computer equipped with midi in/out ports. I bought on in '86 and also bought the seperate DD for it (740K 31/4" floppies single sided) Used it mainly with a music sequencing package by Steinberg called Pro 24. At first I couldn't get used to the GUI, as all I had used previously was computers such as the ZX81 & Spectrum. A great machine!! - author: Matt (Virginia) date: Tuesday 5th March 2002 text: I loved this computer...except for when I was playing a game and that line of bombs came up. :( I wonder what happened to it... related: - /museum/atari-130-st-260-st - /museum/atari-4160-ste - /museum/atari-520-1040-ste - /museum/atari-520-1040-stf-stfm - /museum/atari-falcon-030 - /museum/atari-falcon-030-microbox - /museum/atari-fx-1-sparrow - /museum/atari-mega-st - /museum/atari-mega-ste - /museum/atari-st-book - /museum/atari-stacy - /museum/atari-stylus-st-pad - /museum/atari-tt-030 oc_id: 20 source: url: https://web.archive.org/web/20230602084718/http://www.old-computers.com/museum/computer.asp?c=20 date: '2023-06-02' --- The 520 ST featured same hardware basis and same amount of memory as the [260 ST](/museum/atari-130-st-260-st/). The main difference between them was the built-in ROM TOS operating system and GEM Graphics Interface. In fact, the Atari 520ST originaly came with the OS on floppy as the OS was not completly finished. Very shortly afterward they came with the OS on 6 ROM chips (TOS 1.0). It was first sold in Germany where it met a great success then released in the United States about six monts later. Colour and monochrome version were available. Sadly, users of the colour version couldn't expect programs written for the monochrome version to work until someone wrote an emulator allowing the software written for the monochrome version to run on a colour monitor. Atari was the first company to offer built-in MIDI ports. This made the computer very popular with musicians. One game even used the MIDI conectors (Midi Maze) to connect up to 16 computers together in a MIDI network. The **520 ST+** offered 1 MB of RAM instead of 512 KB. As the main board was designed to provide space for only 512 KB of RAM (16 x 41256 type chips), the second 512 KB bank chips were soldered on top of the original chips. Apparently, 1 Mb versions were sold as Atari 1040s in Australia... The model **520 STM** came with a built-in TV modulator allowing a direct connection with the TV-set. The original Atari 520 ST came with an external 360K single sided 3.5 floppy drive, the SF354. Most dealers either bundled it with separate power supply, or a much neater Cumana or Triangle branded drive at lower cost. --- More information from **Dan Osers**:\ Actually, there never was a colour vs. monochrome version. All ST models featured at least 2 colour and 1 monochrome setting. They were not interchangable, as the highest resolution was only available in monochrome.\ Hence a program has to have different versions (or fat binary) to work on either - but the system supported both. Many games would only run in colour mode, many pro apps only in hi-res mono. Colour monitors generally could not display the mono-hi-res and vice versa, though this was more of a limitation of TV / Monitor technology of the time. About fat binary apps, **Ari Feldman** adds:\ Atari ST apps were NOT "fat binaries" - e.g. two types of executables embedded in the same executables in the same way that apps written for the old MacOS were.\ Rather, most apps supported the ST's color and monochrome resolutions by using different Resource files (i.e. dialog, menu and alert box definitions). These were external files that resided on disc and were loaded in according to the screen resolution being used.\ Some games supported Monochrome directly by adding subroutines to detect what screen resolution was running and adjust themselves accordingly.