Hi, can't help specifically, as I'm looking for the same info
I've tried the VS-840EX upgrade using the midi files that Roland provide, but that fails immediately I press play on my Fantom Xa
and it looks as though Roland have removed the VS840EX zip disk upgrade zip file from their available downloads.
For what it's worth, you can put the VS-840 into the correct mode to u[grade from midi files by holding down
Mode, Input and Enter buttons, then turning the power on. The display will ask "Receive MIDI EX?" to which you press the Enter / Yes button again.
Theoretically, you should then be able to play - on a sequencer, in my case a Roland Fantom Xa - 8 midi files. Roland supply a player that allows you to send the files from a computer, which will probably work if you have a USB-Midi adapter / or joystick midi port on your computer...
Unfortunately, when I try to send the first midi file I immediately get a message saying
Error STOP! Can't VersionUP!
Now, I used that method to upgrade from 1.02 to 1.05 - as the zip disk method gave me a bricked "Bad Flash!" problem, so the method works, but the files on Roland's site for the VS840EX Midi file upgrade do not work, and they've removed the zip disk upgrade download
So, if anyone has that zip disk upgrade, for the VS840EX I'd really appreciate it if it can be emailed to me, or a link posted to somewhere it is hosted.
Regards, and hope this helps