Yo Steve & the Band of Wine:
Don't know about the "card" you seek; but, after reading more of the manual over and over for my 2816, found out that if using the unit and the POWER goes out -- bad things can happen to the HD, as well as the tracks that have been recorded.
So, yesterday I ordered a UPS from Full Compass that will keep power on for eleven minutes which is plenty of time to shut down the unit as directed by the manual.
That's about the only clear part of the manual too.
Thought I'd pass this on to you and others who own a 44 or a 28.
Green Hornet