Hardware Support: SPROG

Supported Hardware

Computer Interfaces

JMRI supports the SPROG both as a Decoder Programmer, and as a mini-Command Station. For more information on these capabilities, see the SPROG manual on the SPROG web site.

Note that there are several different versions of the SPROG hardware, and even more versions of the SPROG software.


In some earlier versions the Firmware Update tool is not completely functional and the firmware update tools in JMRI should NOT be used without first checking the current firmware version (see below) and contacting SPROG DCC to ascertain if that version can be updated by the user.

Under no circumstances should you experiment with the Firmware Update tool if you do not have a valid update file available. Doing so could result in your SPROG becoming non-responsive. It will then need to be returned to the manufacturer (or local representative) for unlocking.



Original SPROGs were connected via a 9-pin serial cable. Current SPROGs are available as USB only.
Connect your SPROG using the appropriate cable and power it up.


  1. USB-connected SPROGs on Windows 10 will work using the standard USB drivers installed in the OS. When you plug in the SPROG, it will show up under Hardware like this:

    If you previously installed some special USB driver, uninstall it on Windows 10 before proceeding.
  2. On Windows 7 and earlier users may need to have a driver installed. For more information on that, see the SPROG manual on the SPROG web site.
    Windows 7 users may also be interested in this video.
  3. Make sure you have the latest version of JMRI. Start one of the JMRI applications.
  4. Go to the Connections tab of the JMRI Preferences pane. This opens automatically the first time a program is run, or you can select it from the "Edit" menu.
  5. Select "SPROG DCC" from the list as the System Manufacturer.
  6. SPROG can either be a stand-alone Decoder Programmer interface, or it can be set to act as a mini-Command Station for running trains.
    You have to select which mode to use in Preferences, and then JMRI configures the necessary options in the SPROG.
    • For DCC programmer operation, select "SPROG" as the System Connection, as illustrated:

      In this mode, the Status Bar along the bottom of the DecoderPro Roster pane will show the inactive function in red, like this:

      If both of hte left hand field display in red type, you may have selected the wrong SPROG System Connection.
    • For Command Station operation, select "SPROG Command Station".
  7. Next, select the proper serial port under Settings. Note that the USB SPROG drivers will appear as a serial port.
  8. Click "Save". You'll be asked if it's OK for the program to quit, click "Yes".
  9. Restart the program. You should be up and running.

Configuring SPROG

SPROG uses a "Mode Word" to set a number of optional operating modes

In all recent SPROGs, the default value for the Mode Word is correct for both programmer and command station modes. For older SPROGs you may wish check or modify the Mode Word as follows:

Open the Command Monitor and the Send Command tools from the SPROG menu. Send an "M" command using the Send Command pane.
You should see a reply in the Command Monitor window, something like:


The h prefix indicates a hexadecimal value. If the value you see is different, then it should be changed by sending the command "M h800". Follow this with the command "W" to save the change in SPROGs EEPROM memory so that it is effective each time you power up the SPROG. Otherwise, the new value will be lost when you power off the SPROG. Please do not be tempted to experiment with other Mode Word values as this could result in erratic behavior of your SPROG.

Identifying your SPROG Firmware Version

Open the Command Monitor and Send Command windows from the SPROG menu and send an "?" command.
You should see a reply in the command monitor window, something like:



SPROG Slots Monitor

SPROG Packet Generator

SPROG Console

Firmware Update

SPROG includes a "Firmware Update" tool that allows the firmware (the internal software that operates the SPROG) to be updated by the user. The tool is only functional in USB SPROG II version 2.2 to 3 and the newer version 4 SPROG.
Warning: see Limitations above.


Third Party info

For more information on the SPROG, see the SPROG web site.
They have a useful FAQ page.

There's a SPROG Yahoo group.

A Dutch-language SPROG Beginner's Manual is available as a PDF from Modelclub De Spoorstaaf.