Poking around with the BIOS and any of the information I can find.

2017/05/11 - I was able to find the location in memory where the splash screen messages were stored. I did not trigger these messages through normal means of running the program normally, just changed the address of what would be printed to the screen. The following are all of the messages I found.

When the CD tray is open.
After a CD has been loaded.
Assuming this is what happens when you put a music CD inside the unit. Is there a GUI player? (Like all CD consoles)
In the early 1990s Sony created the "Sony Data Discman": A Discman with a dot-matrix LCD and miniature keyboard attached. It was a portable e-book reader. All books were loaded from 3in. (8cm) CDs. I assume that this message is referring to the same format of CDs one would use in a Data Discman.
I assume this is what happens when a CD is placed in the unit after the tray has closed and the CD is being "accessed". I do not know if the physical unit has an "access" indicator either.
This should show up after "Start" has been pressed, or for anything else?

Error messages

Perhaps in the process of loading and error occurs. Scratched CD or pulling the CD out during load? Or just corrupted data in general.
Anything that is not a music CD or Super Disc game. I guess they were really calling the games "Super Discs" or else they would have said something else.
EB = Electronic Book? I don't know when this would be triggered. If it is not an e-book, what is it?
Result of an exception handler? Trying to push the physical "play" button on a Super Disc console?
Is this what goes into that "NEXT" port on the back of the console? What is an M-COM? Is this relating to an IC on the actual motherboard of the unit?