I just upgraded the firmware in my newly bought MKS-70 from 1.03 to 1.08. I’m not actually sure what the differences are, but since I have the possibility to program EPROMs there was no reason not to.
However, the engineers at Roland decided to put the EPROM in a position that makes it impossible to pull it straight out. The EPROM is located at the mainboard in the bottom of the MKS-70 and marked with an A. The two voice cards (same as used for the JX-10) are stacked upon that. It is possible to fold away those cards, but a lot of cables has to be detached. I should mention that there each voice card also has an EPROM, these are didn’t have to be upgraded.
The TOP853 couldn’t burn the TC57256D-20 EPROM that are used in the MKS-70 and JX-10. My advice is not to buy the TOP853 if your’re going to use it for programming. The GQ-4X did it after I added a custom line to a new text file called customdevices.txt