Perhaps it is due to it being hard to say whether or not something is dumped or not. What criteria do you use for it not being dumped, because a lot of unknown stuff can be found on the yahoo auctions for instance. Does that qualify?
I have many undumped software, this evening I'll provide a list.
Some of them are here www.msxit.org , the entries with blank-cell in "DUMP" column.
For example those of DAInamic, Geasa, GTS, Philips GB Neue Medien, and other on carts and not listed there (a spanish database on cart, many floppy disks from Philips, etc.).
OK, speaking of which: is it an idea to use some of those pictures on auction sites for Gen MSX (if allowed; I haven't looked at the terms and conditions on those sites): 'cause some have pictures of stuff you won't see very soon.
Also you can already see quite a lot of details on a game to add to Gen MSX. For instance I saw on a screenshot of psychic wars that the price for that software wasn't 8800 yen but 7800 for the msx 1 version (I was checking if it was cosmic soldier 1 but probably that title doesn't exist).
