Mario Semo wrote in a message to Mike Bilow:

 MB> selector is mapped to a 4 KB area of memory.  You cannot 
 MB> then call DosSetMem() to commit more memory than the 
 MB> allocated selector length under any version of OS/2.

 MS> and thats again WRONG! PLEASE try before you write
 MS> something. 

 MS> Under OS/2 WARP GA you CAN:

 MS>  DosAllocMem(1byte,READ/WRITE)
 MS>  DosSetMem(64K,committed) -> OK
 MS>  DosSetMem(64K+1byte committed) -> ERROR

 MS>  so, it appears as 64K IS allocated whatever you say
 MS> refering to ancient OS/2 toolkits prior to DevCon8. 

What seems to happen when you call DosSetMem() to commit residue
unallocated memory is that OS/2 will commit it for you if and only if it
has not been otherwise allocated.  This is essentially an operation which
works by coincidence.  The exact point at which DosSetMem() fails is not
necessarily 64 KB, but varies somewhat unpredictably.
 
-- Mike


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