website/content/museum/atari-520-st-st-stm.md

title, categories, types, origins, years, cpus, params

title	categories	types	origins	years	cpus	params
Atari 520 ST / ST+ / STM	Computers	Home Computer	U.S.A.	1985	Motorola MC68000	name image company company_name specs tabs forum_thread photos adverts hardware emulators links docs related oc_id source 520 ST / ST+ / STM /media/museum/photos/atari_520st_system_1.jpg /companies/atari Atari label value NAME 520 ST / ST+ / STM label value MANUFACTURER Atari label value TYPE Home Computer label value ORIGIN U.S.A. label value YEAR 1985 label value KEYBOARD Full-stroke keyboard with numeric and editing keypads label value CPU Motorola MC68000 label value SPEED 8 mHz label value CO-PROCESSOR 'Shifter' and 'Glue' custom chips label value RAM 512 KB (520 ST/STM), 1 MB (520 ST+) label value ROM 192 KB label value TEXT MODES 40 or 80 columns x 25 lines label value GRAPHIC MODES 320 x 200 / 640 x 200 / 640 x 400 dots label value COLORS 16 among 512 (320 x 200) / 4 among 512 (640 x 200) / monochrome (640 x 400) this last mode needs a special monitor. label value SOUND 3 voices, 8 octaves label value SIZE / WEIGHT 47 (W) x 24 (D) x 6 (H) cm label value I/O PORTS RGB, TV modulator (520STm), Cardridge, Midi (in/out), Centronics, RS232c, Hard Disk, Floppy Disk, Joystick, Mouse label value BUILT IN MEDIA External 3.5'' 360 KB disk-drive (option) label value OS TOS / GEM label value POWER SUPPLY External power supply unit label value PRICE £749 (1985, UK), £399 (1986, UK) photos adverts hardware emulators links docs 40 title subtitle text image ATARI 520 ST it has the same characteristics as the 130 ST and the 260 ST, save for its added memory /media/museum/photos/520st.jpg title subtitle text image 520 ST MOTHERBOARD **(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. /media/museum/photos/atari_520_motherboard_1.jpg title subtitle text image REAR CONNECTORS **(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 /media/museum/photos/atari_520st_back_1.jpg title subtitle text image UK ADVERT One of the first advert for the Atari 520ST checked against an Apple Mac and an Apricot computer. Thanks to **Bradley Sturch** /media/museum/pubs/atari_520st_pub_s2.jpg title subtitle text image SF-354 Single density disk-drive /media/museum/hardware/atari_st_sf354-diskdrive_1.jpg title subtitle text image SF-314 Disk-drive /media/museum/hardware/atari_st-disk-drive_sf314.jpg title subtitle text image CUMANA DRIVE /media/museum/hardware/atari_520_cumanadrive_1.jpg title subtitle text image SUPRADRIVE 20 Mb hard-disk /media/museum/hardware/atari_supradrive_20mb.jpg title subtitle text image 170MB QUANTUM HARD-DRIVE This unit has an ICD Host Adapter. /media/museum/hardware/atari_st_quamtum_hd170.jpg title subtitle text image ATARI MEGAFILE 30 This hard-drive has a 30Mb capacity. /media/museum/hardware/atari_st_megafile30_1.jpg title subtitle text image INSIDE THE MEGAFILE 30 **(1)** Seagate MFM 30 MB hard-disk Type ST-238\ **(2)** Power supply\ **(3)** Logical board\ **(4)** Power and disk access LED's /media/museum/hardware/atari_megast_insidemegafile_1.jpg title subtitle text image MEMORY EXPANSION 512 KB to 2 MB memory expansion, depending of the memory chips used. /media/museum/hardware/atari_520st_memexp_1.jpg title subtitle text image ATARI UNIVERSAL MODEM 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. /media/museum/hardware/atari_520_modemsx212_1.jpg title subtitle text image SML-804 Laser printer 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. /media/museum/hardware/atari_megast_slm804printer_s1.jpg title subtitle text image SMLC-804 Laser printer interface This interface allowed the SML-804 printer to be connected to any Atari ST holding at least 1 MB RAM. /media/museum/hardware/atari_megast_slmcinterface_s1.jpg title url platform text Pacifist ! http://www.pacifist.fatal-design.com/ MS DOS Pretty good emulator title url platform text Gemulator http://www.emulators.com/gemul8r.htm Windows title url platform text MagiCPC http://www.application-systems.de/magicpc/index.html Windows title url platform text SainT http://saint.atari.org Windows The best Atari ST Emulator ! title url platform text Steem http://steem.atari.st/ Windows Excellent emulator for 1040/520 STE ! title url platform text Tos2Win http://www.aixit.com/tos2win/ Windows A good Atari GEM Emulator ! title url platform text MagiCMac http://www.application-systems.de/magicmac/index.html Apple title url platform text NoSTalgia & PowerST http://users.skynet.be/sky39147/ Apple title url platform text STonX Homepage http://www.complang.tuwien.ac.at/nino/stonx.html Unix / Linux title url platform text Atari ST Emulator http://www.atari-st.lovely.net/ Other platform Written in Java ! title url platform text ARAnyM HTTP://ARANYM.ATARI.ORG Multiplatform Multiplatform project title url platform text Hatari http://hatari.sourceforge.net/ Multiplatform 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. title url text Atari & Commodore Home Computer Museum http://www.best.com/~hmk/ title url text Atari Music Network http://www.atarimusic.net/ Atari Music Network welcomes and celebrates all vintage digital musicians no matter what their computer title url text Atari ST Demo History http://wwwbrauer.in.tum.de/~brandtf/ataridemos.html title url text Atari ST Download Area http://www.chebucto.ns.ca/Services/PDA/atari.shtml Atari 400/800/XL/XE & ST/TT/Falcon Software download page title url text ATARI.ORG http://www.atari.org/ Looking for something on any Atari machine ? Follow the links ! title url text Dead Hackers Society http://www.dhs.nu/ Atari demo scene title url text Little Green Desktop http://www.atari.st/ Largest Atari ST ressource! title url text Medusa computer http://www.kingx.com/kingx/medusa/thes.html You can still buy an Atari ST family clone computer title url text MiNTOS Distribution http://www.earth.ox.ac.uk/~steve/mintos.html title url text Musique.Atari.Org HTTP://MUSIQUE.ATARI.ORG Web site dedicated to the ATARI and the Music... title url text PLOPBOX - Atari music archive and jukebox http://www.plopbox.net/ listen to atari tunes directly from your browser title url text Polish Atari Wikipedia http://atariki.krap.pl A lot of info about Atari (in polish) title url text ST Anwender Bern http://my.blackpoint.ch/stab/ Atari ST Usergroup Bern (Swiss) title url text The Atari Historical Society http://www.atarimuseum.com/ The complete history of Atari Arcade and Home games and computers. Complete site with pictures, commercials (streaming), and full text articles. Amazing site ! title url text The Atari ST Quick FAQ http://www.megacom.net/~q-funk/ST/ title url text The Atari WebRing Homepage http://b.webring.com/hub?ring=atari Useful ! title url text The Ultimate ATARI Resource http://www.atari.org title url text What is TOS http://www.vanc.igs.net/~roughley/tos_main.htm title url text Index of -~archive-atari- http://www.umich.edu/~archive/atari/ title url text Web Wiz CAPTCHA http://www.webwizcaptcha.com French forum title url cover text ATARI 520 ST OWNER'S MANUAL http://www.classiccmp.org/dunfield/atarist/index.htm /media/museum/docs/couvs/atari_520st_user_doc.jpg [**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 :** /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 20 url date https://web.archive.org/web/20230602084718/http://www.old-computers.com/museum/computer.asp?c=20 2023-06-02

The 520 ST featured same hardware basis and same amount of memory as the 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.

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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.