INT 67h, 52h GET/SET HANDLE ATTRIBUTES ≥ 4.0
On entry:
AH = 52h
AL = subfunction
00h get handle attributes
01h set handle attributes
BL = new attribute (see returned AL)
02h get attribute capability
DX = handle
Return:
AL = attribute (for subfunction 00h)
00h handle is volatile
01h handle is nonvolatile
AL = attribute capability (for subfunction 02h)
00h only volatile handles supported
01h both volatile and non-volatile supported
AH = status
00h successful
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
8Fh undefined subfunction
90h undefined attribute type
91h feature not supported