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).
AX = 0304H
CX:DX = real mode callback address to be freed
if function successful
Carry flag = clear
if function unsuccessful
Carry flag = set
AX = error code
|8024H||invalid callback address|
- Real mode callbacks are a limited system resource. A client
should release any callback that it is no longer using.