Dear everyone, Despite not having a DTP-H1500 with the 1.50 firmware running on it, I rebuilt what would be the closest approximation of the 1.50 firmware on this unit (using a mix of both the DTP-L1500 and DTP-T1000 1.50 firmwares), it should be pretty close, if not identical to the real thing. I taken the leap have successfully (and forcefully) flashed this on my DTP-H1500 (I did test this on my DTP-T1000 first, just in case) and I am glad to announce that it does work as intended (on both DTP-H1500 and DTP-T1000 units) and even runs plain old vanilla kernel mode ELF (from the DVD drive, the memory stick icon is hidden in the vsh game menu on 1.50 test/tool) How did I flash this you might ask? I first had to downgrade from 6.60 all the way back to 2.60, unlike on the DTP-T1000, on DTP-H1500 the process is rather tedius, you need to go through different update/downgrade processes to achieve this as you can only use specific the downgraders bundled with the firmware you are running on (even if you have another supplied in another updater that downgrades to the same firmware version!) So I went the following route using the updaters/downgraders at my disposal (some may not be public): 6.60A > 6.31A > 6.00A > 3.72A > 3.90A > 2.71A > 1.52 Rev 0001 > 2.60D (I had to update to 3.90 because I did not have the 3.72 Update with the 2.71 downgrader that came with it, using any other 2.71 downgrader would not work on 3.72) I have not tested this method with the 2.60B firmware but I would assume it'd also work on it. Next, I burned the unpatched version of GTA:LCS (the one that has the 2.00 firmware update bundled with it), I used the EU version but I think any version will do, obviously you will need to rebuild the ISO into a proper UMD Master image with the official sdk's umdgen and the decrypted BOOT.BIN file before burning it into a disc, or you could just use the original UMD if you have it. I installed the eloader for 2.60, copied the DOWNDATER FINAL AUTO (which incidentally I totally forgot I helped write back in the days xD), started GTA, selected the downdater from the eloader menu and waited for the downgrade process to be done, and voilà! A DTP-H1500 running on firmware 1.50! Technically you could replace the vsh to the retail 1.50 vsh (it runs on DTP-T1000, I have not tried this on Testingtool however) to be able to use the memory stick in the game category, beware however that UMDs and DVDs will not work using the retail vsh (regular eboots and homebrews will), you should be able to update directly to a testingtool update in EBOOT.PBP form (I have not tested this however, UMD/DVD updates will obviously not work) but if you can't you will be stuck on this firmware, this is something I will need to test first on my devkit. UMD/DVD updates will work using the tool vsh however, which is the one I am using in this firmware. I have created a ready to use pack here: https://drive.google.com/open?id=1ELxFm--TqeX5sMDfOtk3khKPt4Mot01I Which contains the rebuilt firmware, the downdater and eloader builds to copy to your memory stick. This is meant to run with the EU version of GTA:LCS, please adapt this to whatever region of GTA you use (you will need to add those regions savedata) Use this at your own risk, I decline any responsibility regarding what might happen should you use this. Keep in mind that, unlike the DTP-T1000, there is currently no way to unbrick a DTP-H1500 Also please note that the eloader exploit does not work from the 2.60D firmware on the DTP-T1000 (it does work on the DTP-H1500) so I flashed the firmware on my devkits using an ELF from firmware 1.50. P.S. If you want extra safety, you may try this on a PSP-1000 first, provided that it is not a TA-082 or TA-086 and that you procure yourself the GTA:LCS unpatched UMD (or flash the firmware through any other mean). I no longer own a PSP-1000 so I have not tested this but there is no reason for it not to work, just make sure you have a pandora battery and a way to reflash a proper firmware after testing.