http://liggydee.cdfreaks.com/page/6500/
je ferai très attention !
Do NOT try to crossflash between 2.** and 4.** firmwares by using Binflash. This is very likely to DAMAGE your drive or make it INACCESSIBLE!
If you need to exchange master to slave on your NEC ND6500A drive, you should use the NEC ND6500A Reverse ATA firmware package but be sure to follow the instructions:
It it highly recommended to use a slimline to IDE adapter and a desktop PC for this procedure instead of leaving the drive in your notebook. You might be unable to complete this procedure if the drive is still installed in your laptop. The drive has to be attached to the secondary IDE channel, you will probably get an error message on the primary channel.
Boot into plain DOS. A command prompt from within Windows does NOT work.
Execute the file 6500BOOT.BAT
Reboot your PC. The drive should now be recognized as a slave device
Execute the file 6500MAIN.BAT to flash the main firmware
If you want to revert your drive from slave back to master again, you can do so by using the NEC ND6500A Normal ATA firmware package and following the instructions above - you just have to exchange master with slave and vice versa.