Examination mode

Since OS version 02.02, the OS includes an examination mode. In this mode, meant to be used during an examination or test, certain calculator features are locked down, and the calculator presents different behavior to indicate that this special mode is active.

The built-in Link app is used to provide information and certain examination mode-related functionality. However, the examination mode can’t be entered directly from this app.

Behavior in examination mode #

In the examination mode, the Frame on the right, left and bottom border of the screen becomes green, and a flashing R in blue background will be displayed on the status bar. The rate of flashing is reduced after approximately 15 minutes.

The automatic power off period is locked at 60 minutes.

Pressing Alpha then the minus sign key to the left of EXE, (-), causes a message box containing the time elapsed in examination mode to appear.

Unavailable features #

The following features are unavailable in examination mode:

The main memory is still available, but with restrictions: when entering the mode, it is backed up then cleared. When exiting the mode, the backed up memory contents are restored and the changes made while in the examination mode are lost.

Entering the mode #

  • Press [SHIFT] then [AC/ON] to put the calculator in standby;
  • Press [cos]+[7]+[AC/ON] at the same time;
  • Press [F1];
  • Press [F2];
  • Press [EXIT].

Exiting the mode #

Officially, the examination mode can be exited in three different ways:

  • Connecting the calculator to a computer using a USB cable, then selecting Mass Storage mode ([F1]) on the mode selection screen, and on the computer, copy or delete any file on the calculator, then terminate the connection;
  • Allowing 12 hours to elapse. This won’t work if the calculator is restarted or batteries are taken off during this period; if that happens, the timer will reset;
  • Connecting the calculator to another one, not in examination mode but with examination mode support (OS 02.02 or later), through a link cable. To do this, connect the calculator, open the Link app on the second calculator, press [F3] (EXAM), [F1] (UNLOCK), [F1]; or you could transfer any data from the second calculator to the locked one.

Consequence of various actions in examination mode #

Pressing the RESTART button or removing the batteries will not exit the examination mode, but it will reset the “elapsed time” timer, and clear the main memory data entered in examination mode.

Putting the calculator into standby with Shift then AC/On will keep the main memory contents entered in examination mode.

Resetting the main memory while in examination mode has no effect on the backup that was saved when entering it.

In other words, while in examination mode, the OS inhibits any attempt to save the current main memory contents to flash, and when exiting this mode, a backup is restored, making any changes or resets to the main memory irrelevant. Since the storage memory is not available in this mode, it doesn’t need to be erased or blocked, and it’s contents will be available again when the calculator exits examination mode. The flag, or one of the flags, that indicates the examination mode is on is clearly stored in non-volatile memory - the flash.

The effect of the various secret key combinations in this mode, especially bootloader ones, is not well known yet.