Where can i download old versions of firmware for hikvision cameras? I need 5.1.0 or 5.2 firmware for a nc304-xd and nc324xd

[jscarswell420]

I havent been avble to find these firmwares for anything. I found a login to a hikvision ftp server and of course they didnt work. Iver spent hours looking for the older firmware. Please help. Thanks