Free Real Mode Callback Address

Releases a real mode callback address that was previously allocated with the Allocate Real Mode Callback Address function (Int 31H Function 0303H).

Call With

AX = 0304H
CX:DX = real mode callback address to be freed

Returns

if function successful
Carry flag = clear

if function unsuccessful
Carry flag = set
AX = error code

8024H invalid callback address

Notes

Real mode callbacks are a limited system resource. A client should release any callback that it is no longer using.