How do I Flash DM500 Using USB to Null Modem?

Updated April 17, 2017

The Dreambox DM500 is a free-to-air satellite receiver and the smallest of the Dream Multimedia Dreambox range. The DM500 features a 252MHz PowerPC processor and 32MiB of RAM. Running on Linux, the firmware on the DM500 is user upgradeable, either by using the Ethernet network interface or the RS232 serial interface. If the DM500 encounters a problem and locks up, or will not boot, the Ethernet interface may be left unavailable, leaving the serial interface as the only method available to restore the firmware back to its factory default. As most modern computers do not have a serial port, a USB-to-serial converter is used to add a serial port to any computer with a free USB port.

Plug the USB-to-serial converter cable into the a free USB port on the computer and install any software provided with the cable. A virtual serial port will be added to your computer, named "COM1" or similar, which appears to any software as a standard serial port. The serial port will be displayed under the "Ports" section of the Windows Device Manager.

Plug one end of the serial null modem cable into the end of the USB-to-serial converter. Power down the Dreambox and plug the other end of null modem cable into the nine pin serial socket on the back of the Dreambox, labelled "RS232." Power on the Dreambox.

Download the "Universal Dreamup" software available as a free download from the Dream Multimedia web site. Open the file once it has downloaded and run the "DreamUP.exe" file to start the application.

Select the address of the virtual COM port provided by the USB-to-serial converter, using the drop down box next to the "Port" label in the "Universal DreamUP" application. Click the "Connect" button to allow the computer to connect to the Dreambox over the serial link. When the Dreambox is connected, you will see the message "Box attached and ready."

Download the DM500 firmware image from the Dream Multimedia web site. Click the "Flash" button in the "DreamUP" application and select the DM500 firmware image which will have a ".img" extension. Click the "Open" button to start flashing the image. The flashing process will take several minutes and the software and box should be left undisturbed during the process. Once flashed, a dialogue box will appear informing you the process is complete. Close the "DreamUP" application.

Unplug the null modem cable from the back of the Dreambox DM500. Power down the DM500 and leave turned off for 30 seconds. Power the unit back up and it should restart successfully using the new firmware.


If possible, do not use the computer while the flashing process is taking place to ensure nothing interrupts the process.


A serial null modem cable must be used, as opposed to a standard serial cable, as the transmit and receive lines between the computer and Dreambox must be crossed. Standard serial cables will not allow you to connect to the Dreambox.

Things You'll Need

  • USB-to-serial converter cable
  • Serial null modem cable
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About the Author

Gareth Downes-Powell has been writing since 2000. He has contributed to a number of U.K. magazines, including "Web Designer," and has co-written four IT-related books published by Apress and Wrox. He has also worked as a technical editor on a number of titles for U.K. and U.S. publishers. Downes-Powell attended Thanet Technical College, achieving A-Levels in computer science, math and physics.