Thanks for all the help!
I can now safely assume that most (probably all) DSO Quad’s have this extra flash, and so I can make use of it. It would be most annoying if it didn’t work on all the devices, though a workaround could possibly be made even then.
Another interesting piece of information was that all the DSO Quads seem to have ILI9327 LCD, while the original code also supports R61509V.
OK - now is the point to state what mine says:
LCD type is 00000000
Official flash size: 256 kB
Test complete: extr flash at 0x08064000 works.
and I hope that information is nothing bad - for me and my Quad
Heh, ok 
So when did you buy your DSO Quad? Have you per any chance tried QuadPawn or Logic Analyzer on it? Do they work?
It just happens that you probably have the other LCD type… the one that is a bit of a pain to support as I cannot test for it.
Pawn does work fine - and I like some of those Aplications and for that and the possibilities, I like this DSO Quad gadget a lot.
Even if you can not test your stuff with this displaytype - I can allways give you feedback.
Mine is Hardware 2.60 and I bought it really early - and that was around april or may 2011