Just got back from the Universal factory in Tucson. Read your post before going, and asked them your question. Here is what the instructor said:
UNS 1A-- Museum Piece
UNS 1B-- Museum Piece
UNS 1C, 1D, 1K-- was "state of the art" till a couple months ago
600 series software
Zilog Microprocessor
8mb ram (cant hold whole world, but they can customize "the world-- ie we only have world with 5000ft+ runways)
UNS 1D is two box installation (E&E and cockpit)
UNS 1C same stuff, one box (cockpit only)
UNS 1Csp "Short Package" (smaller case) if you have an all digital aircraft.
UNS 1K is two boxes, and a scaled down, smaller cheaper version of the 1c/d.
Smaller screen and keyboard (for smaller install space)
A few less features, but functionally the same more or less
-- not video capable (airshow, upload weather)
--not TAWS (terrain awareness) capable
The Latest and Greatest from Universal:
UNS 1E-- Like the UNS 1C
UNS 1F-- Like the UNS 1D
UNS 1L-- Like the UNS 1K
E,F,L Changes:
Motorola Microprocessor
16mb+ memory
Active Matrix LCD display
Ethernet loader (make disk loads way quicker)
800 Series software, which supports new features
--GLONASS (soviet GPS)
--"Abeams" Points
1C, 1D and 1K can be upgraded to the 800 series software, becoming 1C+, 1D+, 1K+. Screen might be upgradeable to the active matrix also (depends on s/n).
System Software:
6.xx The normal C,D,K stuff
7.xx C,D,K stuff with tactical/SAR features (patern search ect)
8.xx E,F,L software
9.xx E,F,L Software with tactical/SAR features
Hope that answers all you want and then some!