A screenshot of a Multiviewer's output. There are 9 squares in a 3x3 grid, subtitled with their input name. Two (SDI Comp 1/1 and CVBS 2/1) have video inputs, the rest are black.
https://digipres.club/system/media_attachments/files/113/783/063/182/203/748/original/9d9f43cb2836a150.png