Hi all, those who have original garmin maps for the PC and know how to compile display tool: Update to r575 or higher. Please execute the program MdrDisplay on the global index of the map (e.g mdrmap.img) like this: java -ea -Xmx6800m -cp d:\display\dist\display.jar;d:\mkgmap\dist\mkgmap.jar test.display.MdrDisplay MDRMAP.img --print=16 > mdr16.txt (fix the paths to the two jar files, replace the ; by : on linux) The expected result is a rather small text file (~32k) or a crash. Please reply with your results, possibly zipped. I am esp. interested in crashes, but good data also might help to understand a few missing bits. This is about a compression algorithm that is used in some old Garmin maps and I plan to implement that in mkgmap to reduce file size of the global index file. I've attached a sample output for the Adria Topo 2.4 map. Gerd