en:docs:dos:api:int21:58:02

Note: This API call is for DOS and Win16 personality only. Use Family API for portability.

2018/09/07 05:04 · prokushev · 0 Comments

Int 21H, AH=58H, AL=02H

Version

5 and higher

Brief

GET UMB LINK STATE

Family API

Input

AH = 58h
AL = subfunction
    02h get UMB link state

Return

 CF clear if successful
 AL = current link state
		    00h UMBs not part of DOS memory chain
		    01h UMBs in DOS memory chain
CF set on error
    AX = error code (01h) (see #01680)		

Notes

a program which changes the UMB link state should restore it before
  terminating
UMBs will only be available if CONFIG.SYS contains the line DOS=UMB,
  the UMBs have been linked into the memory chain with AX=5803h, and
  the allocation strategy has been set to include high memory with
  AX=5801h
 

See also

#01687,#02766 at INT 2F/AX=4310h

Note

2018/09/04 17:23 · prokushev · 0 Comments