I had the opportunity to buy this recently. It just arrived today, so I haven't taken it apart to document the LoBo(something which I will do in due course). The floppy drive also won't accept a disk, but fortunately I was able to boot it via an external. This was bought from its original owner, and I'll see what I can get out of him about its history. I don't THINK it's had a RAM upgrade. The SN decodes to the 17th week of 1984, which if I'm counting correctly means April 22-27.