MODAM Mac Plus I/F Card

[pocketscience]

Has anyone seen one of these before? A little bit of Googling brought up next to nothing.. I found a thread here with a newer SE PDS variant and that's about it..

I'm guessing it's supports an external greyscale monitor for a Mac Plus? There's some dual port VRAM ZIPs.. Two missing crystals...

 

[lilliputian]

Adrian's Digital Basement did a video recently on a similar device, which he got working with a modern monitor by using an RGB2HDMI:

It ended up being a Radius Full Page Display Card from c. 1986.