Thanks for that info flagmax. I'll have a play with the header info for the rgn made from gmapprom.img for primary map.

Yep knew about the use of RGN_Tool, that's how i made the Pacific basemap into an rgn file which successfully flashed to region 3. I fluked the region change in hex with the basemap, changing the number at 0x32 from 33 to 03 resulted in the Section number appearing in RGN_Tool as xxxx [unidentified] which happens to be correct. I confirmed this by reverse-engineering the Atlantic basemap .rgn which is available here: [Only registered and activated users can see links. ]. When i got the img file [which then works fine], i renamed it to .bin and loaded it to RGN_Tool and remade the RGN. I then compared the 'homemade' one to the known good in hex and found only the one difference 33 instead of 03 at offset 0x32. Fixing that resulting in the files matching of course, so i then did the same with my self-made Pacific basemap rgn and flashed it, works fine as reported in P7. Unfortunately changing 0x32 to 49 with the detail map rgn doesn't result in a successful flash as also reported in P7. Could it be to do with the Section number requiring editing as well? I can't find a detail map as an rgn anywhere to compare any further differences. Do you know where the Section # can be edited by any chance? I'm prepared to experiment with Section # to find the working one. It can't be overwritten in RGN_Tool nor can Region # of course.

I have neither programming skills or background in software so if you can enlighten me, use small words with much soothing cooing please.