[Yaesu] Yaesu FT-101, MJ# to Board ID

[Ken]

Hi Gang,

I have a chart for operating voltages on various pin numbers of the FT-101E 
boards and modules . Down the side is pin #, that, I can figure out. Across 
the top is "MJ" number. How do you correspond "MJ" # to the correct board 
identification. I must be missing something very basic. Or, is this some 
knowledge passed along via DNA to Yaesu owners? What does "MJ" refer to? 
Yaesu identifies it's boards by PB1056, PB1547, etc. I'm missing the 
Rosetta Stone linking the two.

Thanks in advance...

Ken - WA4MNT