Wow. If you have this spare machine with the capacity to take this history data, you have nothing to loose by restoring the data and verifying if the software will work. If there are no errors when you restore the data, seeing whether the software will run will not hurt anything. I can say, if you are simply storing the data and the actual JDE software will be processing on another I-series, where OS-400′s level is supported by JDE for the version you are using, it should work if you don’t have issues restoring the data. I would imagine that the need to do this stems from a fee imposed if you upgrade the machine or change to a new machine. Interesting idea, but I would really cost out the possible savings over three years and make sure the cost of maintenance was lower than the upgrade price. Can you tell us how old this machine is? I can’t remember when I last saw Version 4. You may check the IBM web site to see if IBM still has the information about the version change from the older version to the newer version. Even if there were major DB changes between the versions for OS-400, JDE may not have used the newer features right away and therefore JDE may work on the older OS.
Hope this helps,