msd8x is a TI-84 Plus Flash application which serves as a GUI interface between your calculator's contents and USB mass storage device's contents. Just like usb8x, it only supports the FAT16 file system.
Attach your USB mass storage device to your USB cable and then that to your 84+/SE's USB port. If your flash drive is a common model, msd8x will auto-launch and display directory contents. If not, press the [APPS] key and then select MSD8X from the menu.
Any USB flash drive can be made to auto-launch MSD8X when inserted. If MSD8X does not auto-launch for your particular drive, e-mail the vendor and product IDs for your device to email@example.com and it will be included in the next release of msd8x. You can use a computer to find the vendor/product IDs or you can use USBTools.
When you first run MSD8X, you will be greeted with the main screen displaying the root directory's contents.
The current directory will be displayed at the top of the screen, where "/" is the root directory.
The bottom of the screen displays the options you can perform on files and folders.
The left side of the screen displays the current directory's contents. Pressing [UP] and [DOWN] will allow you to scroll through the directory's files and folders. Any entry with a "+" sign next to it is a folder, and pressing [ENTER] or [RIGHT] on it will go into that subdirectory. If you see ".." in the list, this is a pointer to the parent directory. Pressing [ENTER] or [RIGHT] on it will return you to the parent directory and eventually the root. You can also press [LEFT] at any time to return to the parent directory.
The right side of the screen displays information about the currently-selected file or folder. "Size:" near the top will display the file size, shortened to use KB (kilobytes) or MB (megabytes) as necessary. Underneath that is "Attr:", which will display file attributes such as Hidden, Archived, or Read-Only. Underneath that is the file size in bytes. Underneath that is the file creation date, and underneath that is the file creation time.
Importing 8x* Files as Calculator Variables
Press [WINDOW] to copy an 8x* file's contents to the calculator in either RAM or Flash ROM. Press [LEFT] or [RIGHT] to select either RAM or Archive, then press [ENTER].
Exporting Calculator Variables as 8x* Files
Press [Y=] to add a calculator variable from RAM or Flash ROM to the current directory. Press [LEFT] or [RIGHT] to select the variable to export, then press [ENTER].
Deleting a File or Folder
Press [ZOOM] to delete the currently-selected file or folder. Press [LEFT] or [RIGHT] and then [ENTER] to confirm or cancel.
Create a New Folder
Press [TRACE] to create a new folder inside the current one. Use the keys to enter a new folder name and then press [ENTER] to create the folder or [2ND]+[QUIT] to cancel.
Rename a File or Folder
Press [GRAPH] to rename the current file or folder one. Use the keys to enter a new file/folder name and then press [ENTER] to rename it or [2ND]+[QUIT] to cancel.
Running MirageOS/Ion Programs
Press [ENTER] on a MirageOS/Ion 8XP file to run it. Make sure MirageOS is on your calculator and there is enough free RAM to run the program.
Press [ALPHA]+[A] or [MATH] to bring up the About and credits screen. Press any key to return.
Press [ALPHA]+[V] or  to preview a text file's contents. If the extension is "TXT", you can also press [ENTER] on it. You can press [DOWN] to scroll through the file's contents and [Y=] to return to the beginning. Press [CLEAR] or [2ND]+[QUIT] to return.
Press [ENTER] on an 8XI file to display its image to the LCD. Press any key to return.
If anything goes wrong in msd8x, error messages are displayed. When possible, a specific error message is displayed, but the error code in the title of the dialog box after "ERROR " is most important. These numbers match the usb8x error codes in the usb8x section. Check these to find out more information about what went wrong. If you are convinced something is a bug or otherwise incorrect and have tried everything, e-mail firstname.lastname@example.org for help.