沒有系統卡，840D不能正常啟動的。必須插入PCMCIA卡。

NCU模塊上的數碼管顯示——

0 表示“Real mode may have been switched to Protected mode.”真正的模式可能已經切換到保護模式。

1 表示“Start of download from the PCMCIA card.”開始下載PCMCIA卡

(Number with decimal point 號碼小數點） 表示：“The number of the module that has just been downloaded appears on the status display.”在一些模塊，剛剛被下載上的狀態顯示。

2 表示“Download from the PCMCIA card has ended successful.”下載PCMCIA卡已經結束成功。

3 表示“The debug monitor is initialized.”調試監測初始化。

4 表示“Operating system was downloaded successfully.”  操作系統成功下載。

5 表示“Operating system has started up.”操作系統啟動。

6 表示“NCK software is initialized.” NCK軟件初始化。