--- title: Atari 400 categories: - Computers types: - Home Computer origins: - U.S.A. years: - '1979' cpus: - '6502' params: name: '400' company: /companies/atari company_name: Atari specs: - label: NAME value: '400' - label: MANUFACTURER value: Atari - label: TYPE value: Home Computer - label: ORIGIN value: U.S.A. - label: YEAR value: '1979' - label: END OF PRODUCTION value: '1982' - label: KEYBOARD value: |- QWERTY membrane keyboard, 61 keys\ 4 function keys (Reset, Option, Select, Start) - label: CPU value: '6502' - label: SPEED value: 1.79 Mhz - label: CO-PROCESSOR value: ANTIC (Scrolling, Sprites, Video), CTIA / GTIA (Color, Sprites, Collisions), POKEY (timers, sound, keyboard, serial I/O), PIA 6810 (I/O, including the 4 joystick ports) - label: RAM value: 8 KB or 16 KB (newer models) - label: ROM value: 10 KB - label: TEXT MODES value: 40 x 25 - label: GRAPHIC MODES value: 'several graphic modes, maximum : 320 x 192' - label: COLORS value: |- 16 (each color can have 8 luminances) = 128 colors maximum in the lowest graphic mode (requiring display list interruption to have them simultaneously)\ and up to 256 colors in some specific modes for machines having the GTIA chip instead of the CTIA - label: SOUND value: 4 voices, 3.5 octaves - label: SIZE / WEIGHT value: Unknown - label: I/O PORTS value: Monitor RGB output, RF TV video output, 1 cartridge slot, Atari Serial Input/Ouput (SIO) port, 4 controller jacks - label: OS value: 400/800 OS in ROM - label: POWER SUPPLY value: External power supply - label: PRICE value: $500 (US) tabs: - photos - adverts - hardware - emulators - links - docs - videos photos: - title: ATARI 400 subtitle: '' text: '' image: null - title: THE FLOPPY DISK UNIT ATARI 810 subtitle: '' text: it uses 5.25" floppy disks and can store about 86 KB / disk. image: null - title: THE ATARI JOYSTICK subtitle: '' text: it is the same used with Atari VCS 2600 console. image: null - title: THE ATARI TAPE RECORDER subtitle: '' text: (600 bauds transfer rate) image: null adverts: - title: ADVERT subtitle: '' text: Picture courtesy of [Steve Browning, www.sbrowning.com/vintage](http://www.sbrowning.com/vintage). image: null - title: 'US ADVERT #2 (1979)' subtitle: '' text: |- Advert said: Compare the built-in features of leading microcomputers with the Atari personal computers. And go ahead, compare apples and oranges. Their most expensive against our least expensive: the Atari 400... image: null hardware: - title: INDUS GT subtitle: 5''/14 disk-drive text: The Indus GT Double Density Drive is considered by many the best floppy drive available for the 8-bit Atari's with its digital readouts and smoke plexi cover. image: null - title: ASTRA 2001 FD UNIT subtitle: Dual 5.25 text: Dual 5.25" FDD unit using single side, single or double density floppy drives image: null - title: PERCOM DISC DRIVE subtitle: Advert text: |- March 1983 Advert said: The Percom Data AT-88 offers 88 Kbytes (formatted) in single-density, with plug-in ease of attachment to your Atari. The AT-88 has integral power supply, "no-patch" to Atari DOS and critical constant speed regulation.\ Take advantage of this low introductory price of $488... image: null - title: CORVUS SYSTEMS HARD-DRIVE subtitle: 10Mb hard-drive text: |- This is a 10Mb hard-drive. With up to 8 multiplexers with 8 ports each it's possible to connect up to 64 Atari 800's up to a single 10 or even 20 megabyte Atari system. Still in use Today at the Fordham Prepatory School in the Bronx, NY is a 64 Atari 800 computer network hooked up to a single Corvus Hard drive system ! The Corvus hard disk system also sported a unique and innovative back-up system called "The Corvus Mirror" which was a VCR interface system that allowed you to plug a standard Video Cassette Recorder (VCR) up to the Corvus Hard Drive System to save back-ups of the hard disk onto actual Video Tapes!!! image: null - title: TOUCH TABLET subtitle: '' text: The touch tablet was the best tool for drawing and painting. It shipped with the AtariArtist cartridge. image: null emulators: - title: SIO2PC url: http://www.cswnet.com/~nkennedy/sio2pc.htm platform: MS DOS text: PC emulates Atari Disk - title: Altirra url: http://www.virtualdub.org/altirra.html platform: Windows text: Altirra, an 8-bit Atari computer emulator - title: Atari800Win url: http://www.concentric.net/~Twist/atari800win/ platform: Windows text: '' - title: Atari800Win Plus url: http://a800win.atari-area.prv.pl/ platform: Windows text: Atari 8 bit emulator for windows - title: WAHCE Home Page url: http://www.geocities.com/SiliconValley/Node/4391/ platform: Windows text: '' - title: XFormer url: http://www.emulators.com/xformer.htm platform: Windows text: '' - title: Chris Lam's Website url: http://www.chrislam.co.uk/ platform: Apple text: homepage for Horizon - title: The Atari 800 Emulator for the Mac url: http://www.serve.com/derekl/atari/atari_emu.html platform: Apple text: '' - title: WACKE url: http://www.ctaz.com/~jlfenton/Wacke.html platform: Apple text: '' - title: ACE url: http://www.csh.rit.edu/~shaggy/software.html platform: Unix / Linux text: '' - title: Atari++ url: http://www.math.tu-berlin.de/~thor/atari++/ platform: Unix / Linux text: Unix based emulator of the Atari eight bit computers, namely the Atari 400 and 800, the Atari 400XL, 800XL and 130XE, and the Atari 5200 game console - title: Atari800 url: http://atari800.sourceforge.net/ platform: Multiplatform text: Atari800 is an Atari 800, 800XL, 130XE and 5200 emulator for Unix, Amiga, MS-DOS, Atari TT/Falcon, SDL and WinCE links: - title: 8-bit ATARI Assembly Language url: http://oort.com/turbots/asm.htm text: '' - title: Antic - The Atari Resource url: http://www.atarimagazines.com/ text: '' - title: APE - Atari Peripheral Emulator for DOS and Windows - Home Page url: http://www.nacs.net/~classics/ text: '' - title: Atari 2600-7800 FAQ url: http://www.cs.colostate.edu/~dzubera/2600faq.html text: '' - title: Atari 8-Bit Computers Frequently Asked Questions url: http://www.chez.com/cmpi/paleo/8bits/atari/faq_atar.htm text: '' - title: 'Atari 8-bit computers: 400/800/XL/XE' url: http://www.santellocco.com/ATARI/ text: dedicated website in italian - title: Atari 8-bit New User, Emulator Help FAQ - v2.1 url: http://www.sonic.net/~nbs/new_and_emu.html text: '' - title: Atari 8-bit SpartaDOS Project url: http://www.celebritybase.net/atari8/ text: '' - title: Atari Gaming Headquarters Main Page url: http://www.atarihq.com/ text: '' - title: Atari Magazines url: http://www.atarimagazines.com/ text: Contains the full text of all issues of ANTIC magazine and moste of the STart ones ! - title: Atari XL-XE Games And Demos Page url: http://www.tu-chemnitz.de/~sgl/atari/ text: '' - title: ATARI.ORG url: http://www.atari.org/ text: Looking for something on any Atari machine ? Follow the links ! - title: ATARIARCHIVES.ORG url: http://www.atariarchives.org/ text: Wow! This site is preserving and archiving information about & software for Atari and other classic computers. Everything here is available with the permission of the copyright holders. - title: Dead Hackers Society url: http://www.dhs.nu/ text: Downloads, tools, news and more - title: Homepage Nyman Atari 8 bit url: http://www.geocities.com/SiliconValley/2741/8bit.html text: '' - title: Ken's Atari 8-bit Page url: http://home.columbus.rr.com/ksiders/atari.htm text: '' - title: Mac-Atari Fusion url: http://www2.bitstream.net/~marksim/atarimac/ text: Atari 8bit Resources for Mac Users - title: MacFalkner's XL Homepage url: http://members.aol.com/MacFalkner/atariindex.htm text: '' - title: Personal Atari Web Page url: http://rjespino.tripod.com/atari.html text: jpeg viewer for the Atari 8-bit and some other tools - title: Polish Atari Wikipedia url: http://atariki.krap.pl text: A lot of info about Atari (in polish) - title: Reminiscing 8-Bit Atari Games url: http://www.qlam.com/atari/atari.html text: '' - title: Satantronic Atari Crew, Atari XL-XE and Falcon 030 url: http://www.napri.sk/web/satantronic/ text: '' - title: The Atari 800 XE Laptop url: http://www.benheck.com/Games/Atari_800/Atari_800_laptop_1.htm text: This guy explain how he made a laptop Atari 800 ! - title: The Atari Historical Society url: http://www.atari-history.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: www.ataricave.com url: http://www.ataricave.com text: Atari 8-bit Games reviews, original manuals, music, maps and more! - title: XL Search - The Atari 8-bit File Archive Search Engine url: http://www.newbreedsoftware.com/xlsearch/ text: '' - title: Web Wiz CAPTCHA url: http://www.webwizcaptcha.com text: Programming on the Atari computers docs: - title: ATARI 400 OWNER'S GUIDE url: http://www.trailingedge.com/atari8/ cover: null text: |- [**ATARI 400 OWNER'S GUIDE**](http://www.trailingedge.com/atari8/)written by Atari  compiled/archived by David Williams\  type of document : PDF\  source : [www.trailingedge.com](http://www.trailingedge.com/) - title: ATARI SYSTEM REFERENCE MANUAL url: http://www.classiccmp.org/dunfield/atarixe/index.htm cover: null text: |- [**ATARI SYSTEM REFERENCE MANUAL**](http://www.classiccmp.org/dunfield/atarixe/index.htm)written by Bob DuHamel (1987)  compiled/archived by Ivo van Poorten\  type of document : PDF\  size : 160 KB\  source : [Daves Old Computers](http://www.classiccmp.org/dunfield) **... READ THE ONLINE VERSION BY CLICKING BELOW :** videos: - title: Atari 400 commercial url: https://www.youtube.com/watch?v=5sr28fygmOQ text: 'Length: 28 s' - title: Atari Home Computer laser disc - Introduction url: https://www.youtube.com/watch?v=54mvCo1uq5A text: 'Length: 5 min 20 s' - title: Atari Home Computer laser disc - Conclusion url: https://www.youtube.com/watch?v=vQDQWvwZ-2w text: 'Length: 1 min 30 s' comments: - author: RonF (Illinois, USA) date: Tuesday 1st September 2020 text: I have a 400. I made a keyboard for it as per the article in December 1982 Creative Computing (https://archive.org/details/creativecomputing-1982-12). I bought a kit from some company I cannot remember that upgraded it to 64K (cutting traces and soldering some wires was involved) and installed it. I also bought the Assembler cartridge for it and took a course in how to program it. I had a lot of fun with that machine. It''s in a box in the garage, I should get it out and see if it still works. - author: David Mc (UK) date: Friday 5th October 2018 text: |- I had an Atari 400 when I was about 13. Me and my older brother used to love writing games for it and using it to switch on light bulbs etc. via relays. The joystick ports were ideal for this! When we started working for an electronics firm, we actually used a 400 to control and test digital PABX telephone exchanges and later design 6502-based, fully automated test rigs for the firm. Recently, my mother was clearing out her attic and asked me if ''this'' was any use? It was my old Atari 400! I thought it was long-gone! This year I opened it up, repaired it and finally upgraded it to 48K! - author: WEMEDIA (Italy) date: Tuesday 20th June 2017 text: |- Atari 400 is the best home computer for videogame until Commodore 64.\ I love its vintage look membrane keyboard! - author: memoryalpha date: Sunday 10th April 2016 text: I grew up in middle class family 80’s America. As far as I’m concerned the Atari 400 was THE COMPUTER OF ITS DAY (before the C64 anyway) nothing else came close with graphics and sound. We all wanted the 800 (or an Apple) but all my family could only afford was the 400. We weren’t alone, the 400 outsold the 800, big time. One would troll the back pages of computer magazines (no internet then!) where 48K DIY upgrade kits were available. My uncle, infuriated that we had to buy a “special tape recorder” as a peripheral, wrote a letter to Atari asking for the specifications of the I/O interface so he could build our own cable for use with any generic tape recorder$ Atari complied. Talk about customer service, try that with Apple or MS. The membrane keyboard was perfect for teenaged users like me$ it was impervious to soda and fast food fingers, as was the steel reinforced unit itself. It survived a spinning $ down a flight of stairs unscathed! Like all good things, it was too good to last. Our house was broken into and amongst the few items stolen was my beloved 400. Heaven has a special place for emulator developers, they’ve retrieved my 400 for me and countless others! - author: Eduardo (NY) date: Saturday 22nd June 2013 text: |- Does anyone know if there is a demand for the Atari 400, never opened and the recorder (never opened also) would go for ?\ Is there anywhere I can sell this? - author: Ryan Madison date: Thursday 3rd January 2013 text: You guys are fags!!!!! - author: Patricia Hobbs (Australia) date: Monday 3rd October 2011 text: I have an atari 400 which I would be happy to donate to a museum - author: Patricia Hobbs (Australia) date: Monday 3rd October 2011 text: I have an atari 400 which I would be happy to donate to a museum - author: Kostas Poularakis date: Tuesday 20th January 2009 text: My first computer was an Atari 400 in 1983. I loved that computer. I eventually got an Atari 800 XL with a printer and disk drive. Later on I got a modem too. That was so much fun. - author: Jose Luis Llamas (Mexico) date: Sunday 4th January 2009 text: My first computer was a ATARI 400, one day a disassembly to drive a toy crane, it works!! I made a lot of experiments... those wonderful days... - author: Peter Hurst (UK) date: Friday 21st March 2008 text: |- I loved my 400 - first machine I tried hardware hacking. As stated elsewhere the Joystick ports were capapble of being used as inputs - I remember toying with test circuit and relays to try and do useful stuff. I have a recollection of a joystick port interface to something but I can't remember what. It was a really good hybrid - the 8K roms with Atari games went under the flap and loaded almost immediately, hours of Defender! I later bought the 1050 floppy disk for the Xl range and used it to back up roms with a little machine code bootloader for running the copies and an Atari Basic program to generate the copies. The machine had a hardware and software interlock on the cartridges, the flap had to be shut to power up and the rom checked a memory location for a cartridge and jumped straight to it if it found one. Turned out a simple switch on the address lines was enough to defeat the check and allowed the machine to boot normally with a cartridge in place. I loved the keyboard at first, but don't forget I came from a ZX-81 and the raised edges on the 400's keys made all the difference, it also lasted many years without failing. I was so sad to see the 400 go when I got an ST - author: Dave MacLachlan (USA) date: Saturday 21st April 2007 text: This was the first computer I ever owned. I couldn't afford the tape cassette recorder for storing programs, so I became very adept at memorizing whatever I was working on, and retyping it to work on it some more. Fun stuff! - author: Roy Lowenstein (USA) date: Thursday 28th December 2006 text: I had one of these way back when. I bought it from an employee of Atari that stuffed it with 48k. I had the printer, interface, disk drive, tape drive and modem (can't remember the brand on it) that could go up to 450 baud. The interesting thing about Atari is they had their own version of ASCII called ATASCI and could transmit graphics to other Atari machines when the rest of the world was still looking at rudimentary drawings using letters and numbers. I had a pimative bulletin board writen in assembly language that was a lot of fun. I hated that damn keyboard! - author: J Martin (Connecticut) date: Friday 13rd October 2006 text: The Atari came with 8k upgradable to 16k. In fact the chips that came on the 8k systems were the same as the 16k model, except the upper half of the addresses was disabled (there were two 8K chips if I remember correctly). Supposedly these 8K chips were factory defects where there was a bad bit in the upper half. There was a simple mod (something like jumpering or replacing a diode) that would re-enable that memory, which I did. Sure enough I discovered that there was exactly one stuck bit in a byte in the upper half of RAM that would always stay 'on', which would corrupt BASIC tokens or machine code, causing the computer to freeze when it was executed. I eventually learned to work around in BASIC programs by carefully placing REM statements in BASIC code and JMPs in assembler so that the bad byte wouldn't accidentally fall in real executable code or corrupt program data. Pain in the neck, but worth it for double the memory. Eventually my dad found a replacement RAM chip for it and everything was good. - author: David (Oklahoma) date: Saturday 9th April 2005 text: After playing on the 2600(and being hooked on Activision's Stampede and others LOL) the Atari 400 was a giant leap it seemed. I remember aquiring the tape drive and playing a game called Zaxon or Zaxxon that came on a cassette tape that had to be loaded into the 400 b4 playing...i think i actually spent more time loading or trying to get it to load than actually playing the game, but when it DID work it was an awsome 3-D flight simulator kinda thing that had amazing(for the time,of course) graphics! - author: adamofevil (usa) date: Monday 17th January 2005 text: |- I am sure that a lot of you Atari users once had an Atari 8-Bit computer back in the day. Maybe you still do. You might remember a classic game called M.U.L.E. A game that you wish would have been ported over to the PC but never was. If you are a M.U.L.E. fan like I am, you probably used to have hordes of your friends over your house to play the best 4-man multi-player game ever written! After playing this game for hours upon hours, days upon days, years upon years, finally everyone grew up or grew apart and stopped getting together to play. If you are a M.U.L.E. fan like I am, you probably have done a bit of M.U.L.E. re-searching on the internet, in hopes for one day someone to create an internet capable version of this great classic. Well, I have some very good news for you. If you run Windows (98/XP) operating system, THE WAIT IS OVER!!! Thanks to the authors of the Atari800WinPlus (http://atariarea.histeria.pl/PLus/index_us.htm) and Kaillera (www.kaillera.com), you can now play the greatest multiplayer game ever made with 4 players OVER THE INTERNET! This is not a clone, it is the ORIGINAL M.U.L.E. un-modified! Same graphics, same sound, same game! The only difference is that it looks a lot better on your computer than it did on your TV back in the day! If this interests you, please hop on over to http://atarimule.neotechgaming.com where M.U.L.E. fans from around the world have been gathering and playing online! Some of our members include the authors of the most popular M.U.L.E. web sites such as World of Mule (http://www.worldofmule.net/index.htm) and Extreme MULEing (http://mule.eichberger.net/index.php) and M.U.L.E. Fans (http://www.100hosting.com/mule/). Even the creator of the recent M.U.L.E. clone game Space HoRSE (www.gilligames.com) has joined up with us! Ahh, the feeling of playing with 4 human players again is quite exhilirating! SO, what are you waiting for? Join us now!! http://atarimule.neotechgaming.com. See you there! Adam - author: John Risby (Earth) date: Monday 28th June 2004 text: As Tristan Smith says (on the main page), the Joystick ports were I/O ports and could be used for many things. The 400 was my first home computer (I was 9 or 10). I wired up one of the ports to my bedroom door to create a computer controlled burglar alarm! - author: Nicole Harrington (Ca, MD at the time) date: Tuesday 11th May 2004 text: |- I used to work for a company that was warranty service for Atari. We started with the games then added the computers. I beleive it was 1983 that we started working on POS (point of sale) displays as they called them for atari that were the coolest thing I had ever seen. It was an Atari 400 computer on a display with a big TV. Below was a special interface board and a Pioneer laser disk player. You could walk up to the atari (which would cycle through its default come take a look message) and it would then play the appropriote response back that had been recorded on the video disk. It was quite fast. The "horrible" keyboard made it durable against spillage and such.\ The funniest thing was there was a problem that no one could solve becouse the person who designed the 400 to video disk player interface was angry and refused to tell them how it worked. It turned out that a peice of foam was needed to stop the VD player top from opening if it thought it was at the end of the disk.\ As far as I know this was quite ahead of its time! related: - /museum/atari-1200-xl - /museum/atari-1400-xl - /museum/atari-1450-xld - /museum/atari-600-800-xl - /museum/atari-65-130-xe - /museum/atari-65xep-65xem - /museum/atari-800 - /museum/atari-800xe oc_id: 76 source: url: https://web.archive.org/web/20230607051808/http://www.old-computers.com/museum/computer.asp?c=76 date: '2023-06-07' --- The Atari 400 and [800](/museum/atari-800/) were the first home computers to use custom coprocessors and the first to use "sprites" and special video interruptions like display lists, features that will be implemented later on the Commodore [64](/museum/commodore-c64/) and [Amiga](/museum/commodore-amiga-1000/) (Atari 400/800 and Amiga were designed by Jay Miner). It offered high graphic resolution, lots of colors and great sound capabilities, more than other computers could do then ! The two models had same characteristics, the 400 is the low-cost version, it has only 16 KB (instead of 48 KB), one cartridge port (two for the [800](/museum/atari-800/)) and a membrane keyboard (a typewriter style keyboard one for the 800). Originally, the 400 was sold with 8 KB RAM, but later most 400s were shipped with 16 KB. The 800 was expandable to 48 KB by adding cartridges, as the case opened upwards to reveal 3 slots behind the program cartridge slots. The expansion in the 400 (which had an identical motherboard) was only available by removal of the top half of the case, as it did not open past the (single) program cartridge slot, and was only possible through a registered Atari dealer. The Atari 400 was known inside Atari as code name "Candy". --- **Tristan Smith** adds:\ The keyboard was very much disliked on this thing. There were several replacement keyboards on the market. Some connected via cable to one of the ports (and required a TSR program be loaded). Others required you open the system up and replace the actual keyboard. One that I remember was adhesive! It had all the keys on it with "eraser" type rubber things on the underside. You peeled off the backing and attached it over the membrane keyboard. When you pressed a key, the eraser would press the membrane key. As unresponsive as that was, it was still better than the original.\ Not too many people realized that the Joystick ports were true I/O and could be used to control devices. There were a bunch of items that used the joystick ports. I remember building a phone dialer with them.... **Adin Seskin** reports:\ The sound on these computers was particularly impressive. Apart from 4 square-wave generators, you could covert them to 2 voices with a far greater frequency range, and the voice generator could also produce general video-game noises very easily - explosions, machine noises etc.\ At one point a surprisingly good software-based speech synthesizer was developed, to exploit the sound chip. It had to disable all interrupts, especially video DMA, in order to generate the sounds, which rather limited its use.\ Not many people know that the same sound generator was also used for data encoding when saving programs or data to the cassette or disk systems.