i just got a 850 and was wondering if it is possible to change the splash screen image from a cd like i could with my older n1's or do i have to have a sd card? Thanks 

Sorry that I don't know the 850 - but  I have a 940 and just used the AVIC FEEDS for Windows to do the custom splash screen thing - was silly easy (even for an old guy - literally a 'techno-peasant' like me could do it.) Found it by googling, at the Pioneer website.

There are both iPhone apps and a Windows version of AVIC FEEDS (I got both, not knowing if I needed it or not - not - only needed the Windows version).
 

It does a couple of other simple things - saving POIs and fuel data (yawn). Can't xfer complete custom routes from Google Maps (which is what I would want), only specific POI locations, or as 'favorites' (yawn x 2).

The Windows app let me very easily select, crop and save an image  - then use the AVID FEEDS 'Replicator' to store the image to an SD card (microSD in my case). It saves it as 'wallpaper.bmp' on the SD or microSD card.

***[For reference, the output - 'cropped' file was an 800 X 480 .BMP file at 96 DPI --- So if you use that as a good reference point for preparing your desired splash screen photo or image, the 'crop' result won't be too painful - avoiding chopped off heads - unless you're into that sort of thing - or it's an ex.]

Then had to insert microSD into AVIC prior to power up - then followed the prompts for the rest.

Easy as pie. Hope this helped.

Regards, Bob W. Bristol RI, US

(Now on to custom backgrounds and getting the $&*^%* iPhone 5 functionality working properly)