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Managing Files and Memory

It is sometimes necessary to manage files and memory on the NXT. You can do this by accessing the Memory tab of the NXT window that is launched from the upper left button of the controller.

 

The memory tab of the NXT window provides a graphical overview of memory usage on your NXT. From here you can also send programs, sounds, graphics and other files to your NXT from a PC, and copy and delete files that are already on your NXT.

 

  1. A graphical overview of used and available memory.
  2. The different file categories (programs, sounds, graphics, other...) that take up the NXTs memory. Clicking on a category name will display these types of files in the list.
  3. A list of files in the currently selected category.
  4. Delete. This button deletes any selected files from the NXT.
  5. Download. This button will download files from your PC to the NXT.
  6. Upload. This button will copy any selected files from the NXT to your PC.
  7. Delete all User Files. This button deletes all user files and cleans up the NXTs memory.
  8. Show System Files. Checking this box will reveal all factory-installed files on the NXT.

The NXTs memory

Each NXT has an available memory of about 130.7 kilobytes. Some of this memory is used to store example programs, graphics and sound files that are pre-loaded on the NXT device when you first get it. This leaves about 56 kilobytes for the files you create and download.

Running out of memory

If you run out of memory you can delete some or all of the files on your NXT. To do this, examine the memory overview graphic to the left (1) and identify which types of files take up most memory. Click that category name (2) and its files will be displayed in the list. Select the files you don’t need in the list and click the Delete button.

Deleting all of your files

You can erase all of your created files and clean up the NXTs memory by clicking the Delete all User Files button. This will delete all of the files you have ever sent to the NXT and re-organize the memory to leave the maximum amount free for new files. Doing this will not delete any of the system files that were pre-loaded in the NXT at the factory.

Note: On rare occasions you can get an out-of-memory error message even when the graphical memory overview (1) indicates there is free space available. This is caused by memory "fragmentation." Fix this problem by using the Delete All User Files button but remember to back up any of your essential files before proceeding.

You can also delete files using the icons on the NXT itself. For details, see the NXT Technology section in the printed User Guide.

Freeing up as much memory as possible

If deleting your user files does not free up enough memory, you can also delete the demo and example files that came pre-loaded in the NXT. These files are referred to as system files and take up around 62 kilobytes. The system files include the start-up and other sounds as well as the demo and Try Me programs.

You can always restore the NXT device’s memory back to factory default condition (with all of the system files) by restoring the firmware. See "Restoring an NXTs memory..." below.

To delete system files, check the Show System Files box (8). Then select a file category (2) and choose the system files you want to remove (3). Click Delete for each file you want to erase from memory.

Note: By deleting system files you will free up memory but at the same time also remove features from the NXT. However, you cannot "break" the NXT by deleting system files.

Here is a list of the system files and the features they enable:

Restoring an NXTs memory back to factory default condition

You can restore an NXTs memory back to factory default condition by re-installing the NXT firmware. For details on this operation, see the Help topic, "Updating the NXTs Firmware." Be aware that re-installing the NXT firmware will delete all files in the NXTs memory -- make sure to make a back up of any personal files you want to keep before proceeding.

Copying and backing up files stored on the NXT

To make a back up copy of your personal files or to share files stored on the NXT with friends, you should copy the files off the NXT to your PC.

To do this, first select the file category (2) for the files you would like to back up or share. Select the desired files in the list (3) and click Upload (7). Finally, select the folder where the files will be saved on your PC and click OK.

Sending a file back to the NXT

To send a file back to the NXT, click the Download (5) button. Select the file you want to copy from your PC and click OK.