Atari, a recognized leader in Video Arcade and Home Consumer products ventured into the volatile and still unknown realm of personal computer systems in 1979. Atari created not just a line of personal computers and peripherals, but a line of home computers. Computers designed for the non-technical individual, putting the power of a computer system into people's homes and making them easy to understand, easy to connect together with peripherals, and easy to use.

Unlike computers from Apple, Tandy (Radio Shack) and the even more "hobbyist" S-100 line of computers, the new Atari computer systems would be packaged into case designs that provided form, function and a friendly appearance. The case designs also included a modular approach to enhancements and add-ons.

Atari's low end entry was called the Atari 400. This system was designed more for children in mind, with its membrane keyboard to prevent food or small objects from getting into the keyboard. It had a unique "wedge" shaped design, could connect to a television set and had a door in the center top to install software "cartridges" featuring games, educational and science programs, computing languages and more. The computer originally had 8K of memory, but later models shipped with 16K. The system was advertised as only being able to support 16K of memory, but in fact could be upgraded with up to 48K of memory. Later on in the 400's sales life, Atari sold a factory authorized 48K upgrade kit for the 400 to be installed internally.

Atari's next entry was a high end home computer called the Atari 800. This system was a far more serious contender as it sported a full typewriter-like keyboard, and sported two slots for cartridges under the cartridge door. in the design of the 800, bankswitching and larger sized EPROMs were not envisioned, so adding later programs on cartridge was going to be done by using the second, "right hand" cartridge slot. Soon after the Atari 800's release, lower cost methods for producing larger cartridge sizes were discovered and with the exception of just a small handful of cartridges, almost no "right hand" cartridges were ever needed or produced.

Behind the open cartridge door of the Atari 800 were two latches (later replaced by screws) which when opened revealed an expansion bay within the top of the Atari 800. Unlike other computers, Atari designed the expansion area and its bus slots to be encased in plastic to shield the user from the actual semiconductors and chips of the motherboard. Atari also encased its expansion boards inside of custom cases so that they could be handled as easily and safely as cartridges. This packaging and consumerization of its technology made the Atari line of home computers very user friendly and less intimidating than other competing systems.

This expansion bay allowed for the insertion of "modules" such as the Personality Module that contained the Atari Operating System in Slot #0. Slots #1 to #3 were used for Memory Modules. Atari sold two types of memory modules, an 8K module and a 16K. Third party firms sold memory cards as large as 1MB for the Atari 800. The 4th slot, #3 had several unique address and data lines that allowed it to be used not just for memory modules, but for Video Cards, Parallel/Serial Cards and other more advanced cards.

Another unique feature of both the Atari 400 and the Atari 800 was its peripheral connector. Unlike other competitors which a myriad of edge connectors, ribbon cables and connectors of all shapes and sizes for everything from disk drives to printers to modem, the Atari 400/800 line of home computers utilized a single connector called the SIO bus or "Serial I/O" bus. The port was large with thick, heavy duty connector pins. This ensured the user could only insert the cable one way, and the cable and connector were strong enough to endure even the most fumble fingered user's attempts of mis-inserting the cables.

The SIO bus allowed any kind of device to be connected to the Atari 400/800 computers, and Atari provided a full range of devices. For storage there was the 410 cassette drive and the 810 disk drive. For printing there was the Atari 820 and 822 printers. The Atari 825 printer required the use of a special Atari module called the Atari 850. The 850 had 4 RS-232c industry standard serial ports and a Centronics compatible printer port. The 825 would connect to the 850's Centronic port. Also requiring the use of the 850 and one of its serial ports was the 830 acoustic coupler modem. Unlike today's modems which simply have a telephone cable inserted into them, the 830 required the use of the old Bell rounded earpiece/mouthpiece handset to place on top of the 830's two "cups". Once the handset was placed on the cups, the user would then dial the telephone number using the phone's base. Atari would later introduce a replacement for the 830 called the 835 Direct Connect Modem and this device was an SIO compatible device, therefore not requiring the 850 interface.

On the front of both of the 400 and 800 computers were four controller ports. While their use was primarily for joysticks and paddles used with games, the ports were interfaced to the Parallel Interface Adapter (PIA), a powerful and versatile chip that allowed for output as well as input. Many companies exploited this feature and introduced modems, clock cards, speech synthesizers, even a hard disk system, all of which could be plugged into the controller ports. Atari would later introduce its own line of peripherals for the interface ports called AtariLab.

In 1982 Atari released a replacement to the aging 400/800 line called the Atari 1200XL. This machine came with 64K of built in memory, a new sleek, low profile hi-tech case, and a closed box design with no expansion whatsoever except for the SIO bus. The 1200XL introduced a better OS with new enhancements and features, a self-test diagnostic mode, international character set, and programmable function keys. However, many of these new enhancements caused incompatibility issues which received far more attention than the new features the 1200XL offered. Add to this the lack of hardware expansion to the computer system and the formula for disaster had been made. Users hearing the reviews and rumors quickly rushed out to buy the remaining stock of Atari 800's left in the dealer pipelines. The 1200XL sales were so poor that Atari pulled the plug on the system within months and prepared a pair of low cost replacements with more features that users wanted.

In 1983 users' prayers were answered with the release of the Atari 600XL and 800XL computers. Sharing the same physical style as the 1200XL, Atari corrected several issues with these new machines. The 600XL came with 16K of memory and could be expanded to 64K with a plug in module called the 1064. The 600XL, like the earlier Atari 400, only had television output. The 600XL and 800XL both had the same full typewriter styled keyboards and, while not as nice as the 800 and 1200XL keyboards, they were good all the same. The 800XL featured 64K of memory and both TV and composite output for video. What both the 600XL and 800XL had that the 1200XL lacked was an expansion connector. Called the PBI or Parallel Bus Interface, all of the major signals from the chipset inside of the computer were brought out through this interface. This allowed for 100K bandwidth connections that could be used by memory, disk drives, alternate CPU's, video cards, interface cards and much more. An expansion card cage was planned for the new XL Parallel Bus Interface, but was cancelled just before its release. The 600XL and 800XL still suffered from OS incompatibilities like the 1200XL computer, but by this time Translator disks were now widely available. These Translator disks would load an image of the older 400/800 operating system into memory over the XL OS. This allowed most software titles to now run on the XL machines without problems. The 600XL and 800XL were the first Atari home computers to include the BASIC programming language built-in.

Two additional high-end XL computers were being prepared for release in 1984 called the 1400XL and the 1450XLD. They had all the features of the 800XL but included several built-in peripherals. The 1400XL was packaged in the original 1200XL case design with some minor changes. It featured a built in speech synthesizer and built in modem. The 1450XLD did one better--it came in a slightly deeper case but with space for up to two parallel disk drives installed. Both computers were cancelled before release.

The XL line also had an extensive line of peripherals such as the 1010 cassette drive and 1050 disk drive. For printing, the 1020 color printer, 1025 dot matrix printer and 1027 letter quality printer were released. Released in limited quantities in the UK was the 1029 dot matrix printer. For communications the Atari 1030 direct connect modem was released, which had built in software that would automatically load into the Atari home computer if a disk drive was not powered on upon boot up of the computer. A CP/M box called the 1060 was being prepared, but was cancelled since an expansion card called the 1066 for the 1090: XL Expansion Box was being readied. However, when the 1090 was cancelled all of its expansion cards were cancelled as well.

In 1985, just a few months after Atari's computer and video game divisions were sold to Tramiel Technologies LLC, the "New Atari" unveiled a new line of 8-bit computers. Called the XE Series (XL Enhanced) these would be the Atari 65XE and 130XE. The model numbers stood for their memory size, as the 65XE had 64K of memory and the 130XE had 128K of memory. The 65XE was basically an 800XL repackaged into a gray case with white keyboard, matching the appearance of the new Atari ST 16-bit machines. The Parallel Bus was eliminated on the US version of the 65XE but included in the European version as a port called the ECI (Enhanced Cartridge Interface) and the 130XE included the ECI in all versions. The XE's had an additional new chip taken from the 1400/1450 unreleased computers called FREDDIE which allowed for better memory usage. Several products like AtariWriter Plus and Basic XE took advantage of this new feature and the additional memory built into the 130XE. In 1987 Atari would repackage the XE computer line into a video game console called the XEGS or XE Game System which had built in Missile Command and would come up in Atari BASIC if the detachable keyboard was attached. The XEGS was packaged with a joystick, lightgun and several cartridge games. Atari's last 8-bit computer was released in Europe in 1988. Called the 800XE, it was a 130XE with only 64K of memory and used old inventories of parts and chips which often resulted in timing issues and problems with the systems crashing and freezing.

As with all the previous lines of Atari Home Computers, the XE's were not without their assortment of peripherals. For storage there were the XC12 and limited release XC11 tape drives, and the XF551 disk drive which was Atari's first officially released 360K disk drive. Atari released two XE-style printers, the XDM801 dot matrix printer and the XDM121 impact printer. Two modems were released, the 300 baud XM301 modem and the SX212, which was Atari's first 1200 baud modem. The SX212 was designed to work with both the Atari 8-bit line through the SIO bus, but it also had a standard RS232 connector for use with Atari's higher end ST computers and any other computer with an RS232 interface. And finally, an external 80 column / printer interface called the XEP80 was released, bringing high-resolution, 80 column text output to the Atari 8-bit computers.

The Atari 8-bit line of computer systems is still actively supported with new software and hardware from hobbyists all over the world and more and more new items seem to appear each year. Not bad for a computer system released almost 25 years ago!