Changed Apple II 800kB floppy image type.

The .2mg image format contains a header which is missing from our file. So our file is rather a .po image.

I opted to not add the .2mg header as it is only necessary if the metadata it contains differs from the values "guessed" when using the "naked" .po image format. On the other hand there are image file consumers not understanding the .2mg image format.

.gitignore

@@ -80,7 +80,7 @@ contiki-cc2530dk.lib
 *.S
 *.eth
 *.dsk
-*.2mg
+*.po
 *.atr
 *.d64
 *.d71

tools/6502/Makefile

@@ -66,7 +66,7 @@ endef
 
 $(eval $(call makes,apple2enh))
 
-apple2: contiki-apple2-1.dsk contiki-apple2-2.dsk contiki-apple2-3.dsk contiki-apple2.2mg
+apple2: contiki-apple2-1.dsk contiki-apple2-2.dsk contiki-apple2-3.dsk contiki-apple2.po
 
 contiki-apple2-1.dsk: apple2enh-makes
 	cp ../apple2enh/prodos.dsk $@
@@ -121,8 +121,8 @@ contiki-apple2-3.dsk: apple2enh-makes
 	java -jar $(AC) -p    $@ contiki.gif     bin 0 < ../../examples/webserver/httpd-cfs/contiki.gif
 	java -jar $(AC) -p    $@ notfound.htm    bin 0 < ../../examples/webserver/httpd-cfs/notfound.htm
 
-contiki-apple2.2mg: apple2enh-makes
-	cp ../apple2enh/prodos.2mg $@
+contiki-apple2.po: apple2enh-makes
+	cp ../apple2enh/prodos.po $@
 	java -jar $(AC) -p    $@ menu.system     sys   < ../apple2enh/menu.system
 	java -jar $(AC) -p    $@ ethconfi.system sys   < $(CC65_HOME)/targetutil/loader.system
 	java -jar $(AC) -cc65 $@ ethconfi        bin   < ../../cpu/6502/ethconfig/ethconfig.apple2enh