diff --git a/pandora/retroarch/retroarch.cfg b/pandora/retroarch/retroarch.cfg
index 057dbfdc1e..1c6ebdf4a4 100644
--- a/pandora/retroarch/retroarch.cfg
+++ b/pandora/retroarch/retroarch.cfg
@@ -1,12 +1,15 @@
 ## Skeleton config file for RetroArch
+##  with default values appropriate for Pandora
 
-# Save all save files (*.srm) to this directory. This includes related files like .bsv, .rtc, .psrm, etc ...
+# Save all save files (*.srm) to this directory.
+# This includes related files like .bsv, .rtc, .psrm, etc ...
 # This will be overridden by explicit command line options.
+# Defaults to the same directory as the ROM.
 # savefile_directory =
 
 # Save all save states (*.state) to this directory.
 # This will be overridden by explicit command line options.
-# savestate_directory =
+savestate_directory = /mnt/utmp/retroarch/retroarch
 
 # Automatically saves a savestate at the end of RetroArch's lifetime.
 # The path is $SRAM_PATH.auto.
@@ -15,6 +18,7 @@
 
 # Load libretro from a dynamic location for dynamically built RetroArch.
 # This option is mandatory.
+# On Pandora, it's usually overridden by the launcher script.
 libretro_path = "/mnt/utmp/retroarch/lib/libretro-fceumm.so"
 
 # Environment variables internally in RetroArch.
@@ -28,11 +32,13 @@ libretro_path = "/mnt/utmp/retroarch/lib/libretro-fceumm.so"
 
 # Sets the "system" directory.
 # Implementations can query for this directory to load BIOSes, system-specific configs, etc.
-# system_directory =
+system_directory = /mnt/utmp/retroarch/
 
 #### Video
 
 # Video driver to use. "gl", "xvideo", "sdl" or "ext" (external API driver)
+# On Pandora, "xvideo" and "sdl" are available, and "sdl" is preferred
+#  if using notaz's SDL omapdss.
 video_driver = "sdl"
 
 # Path to external video driver using the RetroArch driver API.
@@ -48,7 +54,9 @@ video_yscale = 1.0
 # video_fullscreen_y = 0
 
 # Start in fullscreen. Can be changed at runtime.
-#video_fullscreen = true
+# On Pandora, this should be false, because notaz's SDL is always fullscreen,
+#  and the hardware scaling only helps if RetroArch doesn't software scale.
+video_fullscreen = false
 
 # Force 16-bit colors. Apparently some video cards in use today have troubles with 32-bit ...
 #video_force_16bit = true
@@ -63,7 +71,7 @@ video_yscale = 1.0
 video_smooth = false
 
 # Forces rendering area to stay equal to SNES aspect ratio 4:3 or as defined in video_aspect_ratio.
-# video_force_aspect = true
+video_force_aspect = false
 
 # A floating point value for video aspect ratio (width / height).
 # If this is not set, aspect ratio is assumed to be automatic.
@@ -73,7 +81,7 @@ video_smooth = false
 # If this is true and video_aspect_ratio is not set,
 # aspect ratio is decided by libretro implementation.
 # If this is false, 1:1 PAR will always be assumed if video_aspect_ratio is not set.
-# video_aspect_ratio_auto = false
+video_aspect_ratio_auto = true
 
 # Forces cropping of overscanned frames. Crops away top 7 scanlines and 8 bottom scanlines. (15/15 for interlaced frames).
 # video_crop_overscan = false
@@ -110,10 +118,10 @@ video_smooth = false
 
 # Path to a TTF font used for rendering messages. This path must be defined to enable fonts.
 # Do note that the _full_ path of the font is necessary!
-# video_font_path = 
+video_font_path = /usr/share/fonts/truetype/DejaVuSansMono.ttf
 
 # Size of the TTF font rendered.
-# video_font_size = 48
+video_font_size = 10
 
 # Attempt to scale the font to fit better for multiple window sizes.
 # video_font_scale = true
@@ -186,6 +194,9 @@ audio_driver = alsa
 # Keyboard input. Will recognize normal keypresses and special keys like "left", "right", and so on.
 # Keyboard input, Joypad and Joyaxis will all obey the "nul" bind, which disables the bind completely, 
 # rather than relying on a default.
+# On Pandora, the included mappings below match the gpio-keys
+#  to the SNES-style controller layout typically used in libretro.
+#  TODO: Decide on good l2/r2/l3/r3 mappings; map analog axes to nubs.
 input_player1_a = end
 input_player1_b = pagedown
 input_player1_y = home
diff --git a/pandora/scripts/retroarch.sh b/pandora/scripts/retroarch.sh
index a78607c762..0805da9939 100755
--- a/pandora/scripts/retroarch.sh
+++ b/pandora/scripts/retroarch.sh
@@ -3,21 +3,19 @@ export PATH="/mnt/utmp/retroarch/bin:${PATH:-"/usr/bin:/bin:/usr/local/bin"}"
 export LD_LIBRARY_PATH="/mnt/utmp/retroarch/lib:${LD_LIBRARY_PATH:-"/usr/lib:/lib"}"
 export HOME="/mnt/utmp/retroarch" XDG_CONFIG_HOME="/mnt/utmp/retroarch"
 
-if [ -d /mnt/utmp/retroarch/share ];then
+if [ -d /mnt/utmp/retroarch/share ] ; then
 	export XDG_DATA_DIRS=/mnt/utmp/retroarch/share:$XDG_DATA_DIRS:/usr/share
 fi
-export SDL_OMAP_LAYER_SIZE="640x480"
-export SDL_VIDEODRIVER="omapdss"
-export SDL_AUDIODRIVER="alsa"
 
+# choose a libretro core.
 cd /mnt/utmp/retroarch/lib
 BACKEND=$(ls -1 libretro*.so | zenity --list --column=Backend)
 cd $HOME
 
-if [ -z "$BACKEND" ] ; then
-	exit 0
-fi
+# if user didn't select a libretro, bail out.
+[ -z "$BACKEND" ] && exit 0
 
+# narrow down the available file formats for the file chooser.
 FILTER='All files (*)|*'
 case "$BACKEND" in
 	libretro-fceu*.so)
@@ -26,13 +24,14 @@ case "$BACKEND" in
 	libretro-pocketsnes.so | libretro-snes9x*.so)
 		FILTER='SNES (*.sfc)|*.sfc'
 		;;
-	libretro-meteor.so | libretro-vba.so )
-		FILTER='GBA (*.gba)|*.gba'
-		export SDL_OMAP_LAYER_SIZE="720x480"
-		;;
 	libretro-gambatte.so)
 		FILTER='GBC (*.gb; *.gbc)|*.gb *.gbc'
-		export SDL_OMAP_LAYER_SIZE="534x480"
+		;;
+	libretro-meteor.so | libretro-vba.so )
+		FILTER='GBA (*.gba)|*.gba'
+		;;
+	libretro-imame4all.so) # does libretro-fba.so belong here?
+		FILTER='Arcade (*.zip)|*.zip'
 		;;
 	libretro-genplus.so)
 		FILTER='Genesis/MegaDrive (*.md; *.gen)|*.md *.gen'
@@ -42,7 +41,26 @@ case "$BACKEND" in
 		;;
 esac
 
-ROM=$(zenity --file-selection --file-filter="${FILTER}")
+# try to point the file chooser at the last used path, if there is one.
+LASTROM=
+if [ -r "${BACKEND}-lastrom.txt" ] ; then
+	LASTROM="--filename="$(head -1 "${BACKEND}-lastrom.txt")
+fi
 
-exec retroarch "${ROM}" -L "/mnt/utmp/retroarch/lib/${BACKEND}" "${@}"
+ROM=$(zenity --file-selection --file-filter="${FILTER}" "${LASTROM}")
+
+# if user didn't select a ROM, bail out.
+[ -z "$ROM" ] && exit 0
+
+echo "$ROM" > "${BACKEND}-lastrom.txt"
+
+# use notaz's optimized driver
+export SDL_VIDEODRIVER="omapdss"
+export SDL_AUDIODRIVER="alsa"
+
+# integral scaling
+export SDL_OMAP_LAYER_SIZE="pixelperfect"
+
+# preload my modified SDL that knows what "pixelperfect" is
+exec env LD_PRELOAD=/mnt/utmp/retroarch/lib/libSDL-1.2.so.0.11.3 retroarch "${ROM}" -L "/mnt/utmp/retroarch/lib/${BACKEND}" "${@}"