2016-03-04 by ritcci@...
I probably shouldnt give any advice because I yanked the disk drive. With that said Im running SE4.0 and there was no upgrading necessary. The OS is on every disk. It loads into the EMAX with the first thing you load and it refers back to it anytime you need to do anything. I dont know what the file structure looks like on the floppies but Im guessing there is an EMX file named something. Possibly EMAXOS.EMX Rename your OS of choice to whatever its called on a proven functioning disk. Load up the emax and whatever OS is on there will load SE or not.
Replace the OS on your floppy with this file and maybe happy time. SE4 (Its just the one Ive had luck with)
Here are all the OS disks
Once you decide which OS you want youll need to copy it to EVERY FLOPPY. Thats precisely why I pulled it out and went HxC. If you have anything besides the first gen of boards you can go SCSI.