LC475 3rd socket?

Seems to me like it's for a ROM SIMM, that they decided to solder to the motherboard instead. Perhaps the early 475s had a removable ROM? Or maybe yours is a prototype?

Yeah, its for a ROM SIMM. All LC475's have those solder pads for it, but I've never seen an LC475 with the actual slot, I'd say that as Gil said, it may have only been in prototype or very early production units. The LC475 came out in October 1993. My LC475 was built that month, and doesn't have one, it just has the pads like the machine on that page, so I'd say that machines with that slot would be fairly rare.

I cannot imagine that it´s a prototype, because it was used by a big press agency here in Austria. On the other hand this could make it possible that it´s an verry early machine. The slot itselve is a little bit smaller than the VRam slots - about 5mm. Not other LC ROM Simm does fit. Are there maybe differences between European and American models?

I"m just curious...what kind of floppy drive does it have? Does it have the older auto-inject floppy drive, or the newer manual inject floppy drive? Just curious, because I know that there was a very rare auto-inject version of the LC475 that only seems to have been sold in a few countries. What month was it built in, out of curiousity? It should say on the sticker on the bottom that has the serial number.

It's not too, too rare, actually. My Macintosh LC 475 also has the ROM SIMM socket (along with a red PRAM reset button) too.

I think most, if not all LC475s have the red CUDA reset button - I have two LC475 boards that have it, but neither of them have the ROM SIMM slot, just the solder pads.

Well, Dana's website said that a later version took out the CUDA button, but I'm not so sure myself.

FYI, my Macintosh LC 475 also has a auto-eject floppy.