How to upgrade DVR System? jeremy January 02, 2018 00:14 Updated Follow How to upgrade DVR System? Related articles 08HA V1.1.6 Upgrade file -- AHD, 720P, 3521a 08HA V1.1.5 Upgrade file -- AHD, 720P, 3521a how to setup your ZOSI DVR system with ZOSI view app? DVR System: how to install and format the hard drive? 04PN V1.2.1 Upgrade file -- rootfs-3520dv300, TVI, 1080P Comments 0 comments Please sign in to leave a comment.