[Elecraft] K3 firmware DSP2 N/A?

[Bill Tippett]

        The download went fine again after in initial glitch which required 
removing power to shut the K3 off.  My heart skipped a beat when it came 
back up with a dark LCD display and the red TX LED flashing.  But then I 
realized it was reloading and all was OK.

        Just for my curiousity, the K3 Utility screen says:

                Installed in K3       Available

MCU             01.48                  01.48
DSP1             01.45                  01.45
DSP2             N/A                    01.36
(DVR)            (N/A)                 (Missing)

(  ) above is light gray...i.e. not active

What is DSP2 above and why is it "Available" but "N/A"?

                                       73,  Bill  W4ZV