Garmin Mobile XT(PPC) able to open 5 maps together.

you must set your map name follow these name….

by 1 map on Device(PPC) and 4 maps on Storage Card

map#1 rename to “GMAPSUPP.IMG” and copy to your device(PPC) in \Garmin

map#2 copy “GMAPBMAP.IMG” (basemap) to your Storage Card in \MiniSD Card\Garmin”
map#3 rename to GMAPSUPP.IMG copy to your Storage Card in \MiniSD Card\Garmin”
map#4 rename to GMAPSUP2.IMG copy to your Storage Card in \MiniSD Card\Garmin”
map#5 rename to GMAPPROM.IMG copy to your Storage Card in \MiniSD Card\Garmin”

NOTE SW.UNL copy to your Storage Card in \MiniSD Card\Garmin\SW.UNL”

I have tested in P535 WM5 GMXT 4.10.20wp-th patched version (by notfaker)

reference site http://www.smart-mobile.com/forum/viewtopic.php?t=123654