I have not checked everything. What I want to now is decode the original maps to find unkown locations, or just to see how are they stored 
Some exmaples:
Junker - Rooms
Junker HQ
Caves
Syd Garden
hey, got that from original code? (the map data) cool, gheh. it's indeed a good way to "sniff" into that monster game. good luck, swah!
Thanks for the explanation D-Tail
I think I have decoded all the maps of the game. At least all the maps pointed in the index table used by the game for loading files. And there is no other unknown places 
I'll try to upload all the maps to my web later today, so you can check how are they stored.
Another thing that can be done is trying to find manually more maps in the game disks. Also, I can try to decode all the graphics to check whether there is unkown art in them.
btw, guillian... I'm interested in that info... Maybe I can help in finding things.
Maps and graphics are stored using a simple algorithm quite similar to RLE.
At sectors 1-4 you can find the index. Each entry takes 8 bytes.
You can know which entries are maps by looking offsets +0, +7. They should be #80 and #01
+2, +3 = Start sector
+4 = Number of sectors to read (size)
+5,+7 = DMA address
It seems all disk have the same index. Perhaps sector 6 is used to know in which disk is the data pointed in each index entry.
This info might be wrong. I have not fully checked it 
ro: what's keeping you? 
guillian: thanks, and that second makes more sense indeed looking at the data