Deciding what to use as the next test rig, since the Beige G3 died. Gonna have to bite the bullet and start recapping/fixing logic boards, but I'm trying to stay focused on PCI card conversions and SCSI-IDE bridges for now. I haven't tried the MDD yet. It has four PCI slots. Also haven't powered it on in six or seven years....
I have never actually seen one of these daughter cards. If one is installed in a Plus or SE, the host machine will not work, because the ROMs have been removed. So the SE is a possible candidate.
Way back in the late 80s, early 90s, Outbound wanted to build Macintosh laptops, but they had the problem of obtaining copies of the Macintosh ROMs.
Their solution was this docking concept. The idea was that one would already own a Plus or SE and then buy an Outbound. After buying the Outbound, the ROMs would be removed from the Plus or SE and the docking card installed. After that, the Plus or SE would not boot stand-alone any more, but would have the capability to dock with the Outbound which now contained the ROMs.
If the card is fully installed according to instructions, there should be a ribbon cable with a Hirose DX connector (looks like mini-centronics) coming out of the lower vents on the right-hand side of the Mac Plus. On the SE, I'm not certain, but expect that instead of using the vent it would use the rear punch out panel.
It is extremely unlikely that your machine has one installed, but I keep hoping...
There were never that many Outbounds. Only the Model 125 had the docking scheme and even for that one, after a while, Outbound just started buying old Macs on the used market and started shipping laptops with ROMs installed, and mostly ended the docking concept.
If a person encounters a Mac with the docking card, they see a Mac that doesn't work, so most folks are likely to dispose of it. I suspect that many/most of the not-too-common Macs with docking cards have already been scrapped.
But again, I keep hoping.
Please let me know what you find.
Jeff