2158
Category: DOS kernel
INT 21 - DOS 2.11+ - GET OR SET MEMORY ALLOCATION STRATEGY
AH = 58h
AL = subfunction
00h get allocation strategy
Return: AX = current strategy (see #01679)
01h set allocation strategy
BL = new allocation strategy (see #01679)
BH = 00h (DOS 5+)
Return: CF clear if successful
CF set on error
AX = error code (01h) (see #01680)
Notes: the Set subfunction accepts any value in BL for DOS 3.x and 4.x;
2 or greater means last fit
the Get subfunction returns the last value set
setting an allocation strategy involving high memory does not
automatically link in the UMB memory chain; this must be done
explicitly with AX=5803h in order to actually allocate high memory
a program which changes the allocation strategy should restore it
before terminating
Toshiba MS-DOS v2.11 supports subfunctions 00h and 01h, as does the
TI Professional MS-DOS v2.13
DR DOS 3.41 reportedly reverses subfunctions 00h and 01h
SeeAlso: AH=48h,AH=49h,AH=4Ah,INT 2F/AX=4310h"XMS",INT 67/AH=3Fh