Good Question, I didn't ask. I did call and said "I was talking to Geoff on DRN and he said you would upgrade older units for $20" Geoff wasn't in the shop but the lady who answered the phone confired it and said probably by Mid Nov. they will be ready. She took my e-mail address and put me on the list to contact when they are ready.
Just a guess, since Geoff said the new units will have increment changes and faster speed updates I'll bet it's a computer replacement.
Rod