Int 27  - DOS 1+ - Terminate And Stay Resident                             [D]

   DX = number of bytes to keep resident (max FFF0h)
   CS = segment of PSP

Return: never

Notes: this is an obsolete call
   INT 22, INT 23, and INT 24 are restored from the PSP
   does not close any open files
   the minimum number of bytes which will remain resident is 110h for
     DOS 2.x and 60h for DOS 3+; there is no minimum for DOS 1.x, which
     implements this service in COMMAND.COM rather than the DOS kernel

See Also: INT 21/AH=31h