I have no idea what it is....but what I will say, is that I don't think thats a Mac part at all. For a start, the ports aren't mounted in the correct way for any model Mac. Secondly, the board doesn't appear to have a chipset or really any other circuitry of any kind. Thirdly, the 96 and 120 pin EuroDIN connectors used for PDS and NuBus slots were/are used for a lot of purposes which have nothing to do with Macs.