Sitting on a riser card, the VDM-2021 is a reproduction of the original 1076 Processor Technologies VDM-1 video / display S-100 controller.
I traded a non-working original VDM-1 for the replica VDM-2021. It worked great. The only issue is that as received the connector coming off of the card is in a bad spot and needs to be moved. For testing I simply put the card on a riser.
As ALWAYS with this IMSAI 8080, one of the first I owned, it's always in need of some repairs. A few keyboard wires are in need of suring up. I can't do much until the connector wires are cleaned up. I am temporarily using an aligator clip, etc.