I thought someone recently posted the flag for this, but I guess not.

 I realise that this flag isn't listed in the manuals or online help, but it took 
me less than 5 minutes to dig through a couple of refrences to find a program that
used the flag. From there all it required was a simple comparison of flags.

 So, here's some info...

    If you don't have a program example showing how to use SuperBitmaps in windows,
    you should get bb2guide off aminet right now. It lists commands from Bums 
    1-7 and is always a handy reference to have around. The program example is
    listed there and in Bum 5.

 The flag....

    $80

 A little more about flags.. (For those who are interested)

    Flags (listed in hex) are quite easy to figure out. They run in patterns, so
   looking for a flag (or finding which flag you need) is quite easy.

 Flag patterning (IN HEX!)
   
   If you look thru the blitz manual, you'll notice that it starts out like this:
   
   $1 .. $2 .. $4.. $8. That is the start of the pattern. Notice the rest of them
   are the same with zeros added. Like $10, $400, $1000 etc etc.. See the pattern?
   (Also note that if you combine $1+$2+$4+$8 it is $F (15) so it doesn't change
   the spot to the left.)
   
   In this case, the flag was $1489. I know that $1000, $400 and $9 ($8 + $1) are
   real flags. Hmmm... $80 isn't listed. Ah ha!
   
I hope someone finds the usefull...