INT 21,4A - Modify Allocated Memory Block (SETBLOCK)

AH = 4A

BX = new requested block size in paragraphs

ES = segment of the block (~MCB~ + 1 para)

on return:

AX = error code if CF set (see ~DOS ERROR CODES~)

BX = maximum block size possible, if CF set and AX = 8

- modifies memory blocks allocated by ~INT 21,48~

- can be used by programs to shrink or increase the size

of allocated memory

- PC-DOS version 2.1 and DOS 3.x will actually allocate the largest

available block if CF is set. BX will equal the size allocated.

- see also ~INT 21,49~