The Atari 1200XL Computer

A favourite among Atari hackers and collectors, the Atari 1200XL was the first of the XL line of 8 bit computers that followed the Atari 400 and Atari 800 computers. While there is much to appreciate about the 1200XL, it was generally not well received when initially launched in 1982.

Atari 1200XL

“Your new Atari 1200XL Home Computer is one of the most powerful and versatile small computers you can buy for the home. It’s a practical computer with a functional, low-profile design that complements any home environment.” — The Atari 1200XL Home Computer Owner’s Guide

The Atari 8 bit line of computers were sold from 1979 to 1992 – a 13 year life span for a technology which didn’t change or update much since it’s initial release. The 1200XL represented the first and most significant revision of the Atari 8 bit line following the original 400 and 800 systems.

Model(s) Released Discontinued
Atari 400/800 1979 1982
Atari 1200XL 1982 1983
Atari 600XL/800XL 1983 1985
Atari 65XE/130XE 1985 1992
Atari XEGS 1987 1992

The 1200XL had the shortest production life of all of the Atari 8 bit computers and was released only in North America (NTSC). As a result it is rarer than the other 8 bit computers from Atari — which is a quality that collectors appreciate.

The Atari 400 and 800 had a memo pad mode which allowed you to type … memos. Basically it let you test out the keyboard straight away when the computer was first turned on.

Atari removed the limited memo pad mode on the 1200XL and introduced the Self Test. This was more practical and allowed users to test the computer’s memory, sound generation capabilities and the functionality of the keyboard.

1200XL Easter Egg : During the self test select all tests. After going through the memory and sound tests you will arrive at the keyboard test. Notice the name that gets quickly typed into the on-screen keyboard. Michael Coulburn was the software engineer who wrote the 1200XL’s self test mode.

The 1200XL had a full 64K of RAM and a newly revised and expanded 16K Operating System. It had a single motherboard which consolidated the multiple boards of the previous generation computers.

As with the Atari 400 and the 800, the 1200XL did not have the BASIC programming language built-in. It required a separate plug-in program cartridge for BASIC.

When you inserted a Program Cartridge into the 1200XL it would conveniently disappear into the side of the unit. The 400 and 800 allowed you to drop their covers down to conceal their cartridges. The rest of the Atari 8 bit computers had their cartridge ports directly on the top of the computer, or on the back.

Two joystick ports

Some of the initial negativity that the 1200XL would receive was due to the missing features of the new system when compared to the original 400 and 800 computers.

Although very little software supported all four of the joystick ports on the 400 and 800, many Atari fans were disappointed that the 1200XL arrived with only two joystick ports. In fact, no Atari 8 bit computer released after the 400 and 800 would have four joystick ports.

Of the disappointed were the multi-player fans of Asteroids, M.U.L.E. and a handful of other games. Atari’s own Super Breakout game allowed up to 8 simultaneous players using their Paddle controllers on 400s and 800s — but only half as many could play simultaneously on the 1200XL.

As you can see in the image above, the joystick ports on the 1200XL were set at an angle which made them easier to access. The XL and XE computers that were released after the 1200XL would not have angled joystick ports. This feature was later re-introduced with the Atari XEGS.

Limited expansion capabilities

The Atari 1200XL lacked any form of internal expansion slots like the 400 and 800 provided. It also lacked external expansion capabilities such as what would later be introduced in the 600XL and 800XL as the Parallel Bus Interface (PBI for short).

Atari’s 130XE (as well as their European 65XE and 800XE models) later introduced the Enhanced Cartridge Interface (ECI) port. These were functionally compatible with PBI ports but not physically. Adapters would later be created to allow PBI devices to be used on machines with ECI ports and vice versa. The Atari 400, 1200XL, XEGS and the North American 65XE all lack PBI/ECI expansion ports.

While the 1200XL had a large and roomy case, there was no way to expand it as it arrived from the factory. However, the 1200XL already came with 64KB of RAM and while many complained about it’s lack of expandability — for most people it simply didn’t matter. Even to this day there are very few PBI and ECI devices available.

The 1200XL SIO Port Problem

Atari 1200XLs (like all Atari 8 bit computers) have a Serial Input/Ouput (SIO) port. One of the engineers behind designing Atari’s SIO was Joe Decuir who would later go on to develop the USB standard. However, the SIO ports on 1200XLs do not have their +12 volts power line hooked up internally. This made them incompatible with some SIO devices that required 12 volts.

Fixing the SIO port is one the easier and most common upgrades for the Atari 1200XL.

Composite-only monitor support

The Atari 400 lacked a monitor port altogether and was only able to connect to a television using RF (Radio Frequency). The 800 did have a monitor port which allowed it to connect to monitors using higher quality signals. The 1200XL also provided a monitor port but unlike the Atari 800 it was only able to output composite signals rather than the higher quality result of separated chrominance and luminance (s-video).

The 1200XL lacks the chrominance video signal on pin 5 on the Monitor port but it is supported on the motherboard. This is another common upgrade for 1200XLs which enables them to support higher quality video output.

Animated Atari Rainbow Logo

A unique feature of the 1200XL is the display of an animated Atari rainbow logo when the computer is turned on without a cartridge or a powered disk drive. Pressing the Help key while this logo is displayed will bring up the computer’s self test mode.

Quality Keyboard

One of the best features of the Atari 1200XL is it’s high quality keyboard. A superb keyboard that also introduced a few enhancements including the new HELP key as well as four programmable functions keys (F1, F2, F3, F4).

“If you’ve used a typewriter, you’ll know how to use the keyboard of your Atari 1200XL Computer.” — The Atari 1200XL Home Computer Owner’s Guide

The keyboard click sounds and system beeps on the 1200XL (which were output through the built-in speaker on the 400 and 800) are passed through to the television or monitor speaker.

The 1200XL is the only Atari 8 bit computer that features two LED indicator lights (L1 and L2). L1 lights up when the keyboard has been disabled and L2 lights up when the keyboard is using the (newly introduced) International Character set.

Redefinable 1200XL Function Key Behavior
F1 Cursor up
SHIFT + F1 Cursor to upper-left corner
F2 Cursor down
SHIFT + F2 Cursor to lower-left corner
F3 Cursor left
SHIFT + F3 Cursor to start of physical line
F4 Cursor right
SHIFT + F4 Cursor to end of physical line
Non-Redefinable 1200XL Function Key Behavior
CONTROL + F1 Keyboard enable/disable (console keys not affected)
CONTROL + F2 Screen display enable/disable
CONTROL + F3 Key click sound enable/disable
CONTROL + F4 Domestic/International character set toggle

Upgrading the 1200XL

The 1200XL is a favourite among Atari 8 bit hackers. With ample space inside the case it’s easy to work on and there’s lots of room for extra hardware components. Most of the chips on the motherboard are socketed which makes them easily replaced without soldering. Some argue that the 1200XL has the best keyboard and most attractive design of any 8 bit Atari. This makes it a great foundational choice for an upgraded Atari 8 bit computer.

Here are just some of the upgrades you can do with a 1200XL.

  • ROM Upgrades such as the APE Warp+ OS 32-in-1.
  • RAM upgrades (256KB, 512KB and 1MB are possible).
  • Add a second sound (Pokey) chip for Stereo sound and up to 8 voices.
  • Super video upgrade.
  • SIO Port fix.
  • Adding a PBI port.
  • 7.16Mhz CPU Accelerator

“Without software, computers are little more than elaborate electronic gadgets. It is software — the step-by-step list of instructions also known as a program — that adapts your computer’s abilities to a specific job, whether it’s storing names and addresses, becoming your personal bookkeeper, or giving you a video arcade at home.” — The Atari 1200XL Home Computer Owner’s Guide


Atari’s 1200XL is a beautiful computer that had some shortcomings — all of which can be overcome. It represents the largest revision improvement in the history of the Atari 8 bit line and set the stage for the XL and XE systems to follow.

The 1200XL had a terrific keyboard, 64K of RAM and a quality form factor. Like most Atari 8 bit computers, it’s possible to upgrade the 1200XL significantly. Despite the initial reception, the 1200XL remains a jewel of Atari 8 bit fans to this day.


  1. The 1200XL rocks. It’s got more style and a nicer keyboard than most of the other 8 bit computers in it’s day. I still have my original unit which I bought new when I was much younger.

  2. I every time spent my half an hour to read this website’s articles or reviews every day along with a mug of coffee.

  3. yup, i had a 130xe, 400 and a 800xl, got rid of all of them, but will never get rid of my 1200xl

  4. Squiggy says:

    Out of all the Atari computers I believe this one is by far the most beautiful, it really is a work of art.

  5. mr sigue-sigue says:

    I just got mine today!
    It joins my existing 800 (unmodded), 800xl (rambo 256k, svhs mod), 130xe (yet to be modded) and 600xl (64k mod, svhs mod)
    I plan to do the svhs mod, the SIO voltage mod and put in an ultimate 1mb so I can preselect the required OS for maximum compatibility.

  6. My first Atari 8-bit was a 130XE, but I eventually switched to an XL with plans to upgrade beyond a stock 130XE, because due to the late arrival and high price of XE peripherals all of mine were from the XL line and I always hated the XE computer not matching my peripherals. The 1200XL was the natural choice for me for several reasons including not only a much superior keyboard, but the best one for any Atari 8-bit and it’s overall style was more refined than the later XL and XE models, The much preferred (by me) easy access side cartridge port (I always felt the later XL’s top cartridge port to be ugly and make the machines look more like a toy console than sleek computer) and large case with plenty of room for upgrades.

    • Also, I never used the PBI/ECI port when I had one, so the lack of one on the 1200XL was a non-issue for me.

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