by Mark Nobes, chief editor

As soon as Atari released the 2600 games console in 1977, the company were already working on the next generation console with much improved graphics and sound capabilities. However, when companies such as Apple and Commodore started releasing some of the first home computers, Atari decided they wanted to create their own computer.

The 400 and 800 models were the very first Atari Home Computers and featured a full keyboard, although this was an awkward membrane one on the 400.

Atari 400 Home Computer - public domain image
Released in November 1979, both machines used the ANTIC and GTIA chips (earlier models used a CTIA chip) to give 256 colours (this was almost unrivalled at the time) with a display of up to 320 x 192 through 14 graphics and text modes. For the techies amongst you, the machines also used raster interrupts and could display 4 sprites.

Graphics 9 mode allowed the machine to display gray-scale digitized photographs, which were very impressive at the time.


All of the Atari 8-bits came with the Atari BASIC programming language, and from experience I can tell you that this wasn't as easy to program as many other versions around at the time, but could produce really good results when you got the hang of it. Atari had intended to use Microsoft BASIC, but couldn't fit it onto the 8kb ROM cartridge.

Originally, the smaller 400 was supposed to have only 4kb RAM, but the falling price of memory meant that 8kb was fitted on both models.

Despite its dodgy keyboard, Atari sold twice as many 400's as 800's. The fact that it was cheaper probably helped, but it also looks more like a gaming computer than it's bigger brother, which may have been more appealing to youngsters during the early 80s. There was also little support for the extra cartridge slot on the 800 by developers.

Atari-800-Computer Public Domain Image
By Evan-Amos [Public domain], from Wikimedia Commons

What were the main differences between the first two Atari computers? Well, the 800 featured a proper keyboard for a start, making it look more like an actual computer. It also had an extra cartridge slot, and memory slots that were expandable up to 48kb.

However, like the 400 it used the MOS 6502 CPU, along with same combination of ANTIC and GTIA chips to provide graphics, and the POKEY chip to handle sound.

Interestingly, other rival computers of the time such as the Commodore PET and Apple II also used the same CPU processor.

Atari 410 Program Recorder
An Atari 410 Program Recorder. It was noisy, unreliable and took an age to load anything, but this is what we had to put up with in the early 80s. The photo features a later model which looks quite different to earlier models.
This video clip gives an example of programming in Atari BASIC to produce a simple display in Graphics mode 8. This brings back so many memories for me - I remember those plot and drawto commands!
Atari User Magazine - December 1986
Atari User was aimed at readers who owned the later XL and XE computers. As with many computer magazines at the time, it featured type-in listings, hardware projects and software  reviews. As the popularity of the 8-bits grew during the 1980's,  The 800XL went on to become Atari's biggest-selling home computer.