The reason why

The Atari 400, 800 and 1200XL all have a special feature{1}: no specific program or language is included in the computer itself, in ROM, on the motherboard.

{1} The Atari 600XL and 800XL and all their successors have, at the very least, Atari BASIC included on the motherboard "as if the Atari BASIC cartridge were inserted in the computer". It can be disabled — that it "made inactive" — by pressing the "OPTION" key during computer start-up.

The reason is logical: it's useless. Unlike other computers of the same era, Atari computers are user-friendly, allowing users to easily load a program{2} or game{2} or language from cartridge, cassette tape or diskette, without typing any commands on the keyboard. Please read the article "How to run a program on tape, diskette, cartridge" in the knowledge base for all details.

{2} That is true for professional programs or games written in machine language. Other specific programs or games, to load from cassette tape or diskette, and written in BASIC require the use of the Atari BASIC cartridge, and the typing by the user of the CLOAD, LOAD "C:" or LOAD "D1:MYPRG.BAS" instruction on the keyboard — as always clearly indicated in the manual, including the name of the file to load for diskette-based programs.

If no software is loaded, the Atari 400 & 800 both switch to the Memo Pad, whilst the Atari 1200XL remains on the superb Atari rainbow boot up logo.

Atari 400 & 800, Memo Pad

Atari 400 & 800, Memo Pad

Atari 1200XL, Rainbow boot up logo

Atari 1200XL, Rainbow boot up logo


According to Wikipedia:

When no software is loaded, rather than leaving the user at a blank screen or machine language monitor, the OS goes to the "Memo Pad" which is a built-in full-screen editor without file storage support.

The memo pad is therefore an elegant and safe solution found by Atari to avoid scaring the novice user who simply hasn't loaded any programs into memory.
Leaving the user with a black screen might lead them to believe that "something is broken".
Leaving the user with an error message such as "No software was loaded" is a negative message, something to avoid for first timers.
Offering the novice user an expert program such as a machine language monitor would have been an aberration for a user-friendly computer as "fall back" solution when no other software is loaded.

Capabilities and limitations


In Memo Pad, you can familiarise yourself with the keyboard of the Atari 400 and 800. All the text-editing functions found in Atari BASIC, for example, are available. So it's the perfect place to practise deleting a line, inserting a character, switching to "reverse video" mode (with the "Atari" key) and back, using semi-graphic characters, clearing the screen, etc... in complete safety and without any consequences, since the computer doesn't interpret anything at all.

There is no risk of erasing a programme on diskette or cassette tape. Nothing serious can happen to the computer as long as you stay in the Memo Pad. If you stop typing for several minutes, the "Attract mode" will be triggered automatically, so you won't damage your CRT screen if you use one. It's like a totally safe playgroud.


In the Memo Pad, you can't save or print what you've typed. This is vital information. Anything you type into the Memo Pad will be irretrievably lost anyway. The Memo Pad is not a word processor because it is impossible to save what you type.

If you exit the Memo Pad in any way (Reset, Power Off/Power On, Opening the cartridge lid/door, etc) you will lose everything you have typed.

As in Atari BASIC, the editor is set so as not to use the first 2 columns (1 and 2). All the content is therefore displayed from the 3rd column (3 to 40) on.
In Atari BASIC, a simple instruction can be used to change this setting, to start displaying in any column. In the Memo Pad, it is impossible to change this setting.

In Atari BASIC, a simple instruction can change the colours displayed on the screen. In the Memo Pad, it is impossible to change the colours.

In fact, you can't change a thing because nothing you type is interpreted by the computer.


These are speculations and interpretations from users and enthusiasts, as the exact intended purpose of the Memo Pad by Atari is not explicitly documented. For this section, I was also inspired by a very interesting discussion on the AtariAge forum. Here is a list of relevant suggestions:

How do I know whether I'm in the Memo Pad or BASIC?

This may seem like an absurd question: if the Atari BASIC cartridge is not inserted in the computer, I must be in the Memo Pad! And vice versa!
It's partly true. If the Atari BASIC cartridge is properly inserted in the computer, you can be either in Atari BASIC or in the Memo Pad.
How can you tell the difference?

If you don't touch the keyboard, it's easy.
Atari BASIC displays a "READY" message.
The Memo Pad displays the message "ATARI COMPUTER - MEMO PAD" at the very top of the screen.

Atari 400 & 800, Atari BASIC

Atari 400 & 800, Atari BASIC

Atari 400 & 800, Memo Pad

Atari 400 & 800, Memo Pad

But if you clear the screen, you won't be able to tell the difference so easily. You can still tell them apart.

Does the "READY" message appear after typing an instruction such as END or PRINT?
If so, you are in Atari BASIC
If not, you are in the Memo Pad

For the video: Altirra emulator, Atari 800, NTSC, OS rev. B, Atari BASIC Rev C. cartridge inserted.


For the video: Altirra emulator, Atari 800, NTSC, OS rev. B, no cartridge.


How to go to the Memo Pad?

There are several possibilities:

Memo Pad and Atari BASIC - What is left behind?

Two things to bear in mind:

  1. When you leave Atari BASIC for the Memo Pad, your Atari BASIC program is safely stored in memory.
    You will find it again, intact, when you leave the Memo Pad for Atari BASIC, by pressing the "SYSTEM RESET" key.
  2. When you leave the Memo Pad for Atari BASIC, everything you have typed into the Memo Pad is irretrievably lost.
    Once back in Atari BASIC, if you decide to go back to the Memo Pad once again, you will find an empty screen in the Memo Pad.

For the video: Altirra emulator, Atari 800, NTSC, OS rev. B, Atari BASIC Rev C. cartridge inserted.


Knowledge base article: kb-software-0002-atari-8bit-400-800-memo-pad
REV. 001.

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