Free DOS Memory Block

Frees a memory block that was previously allocated with the Allocate DOS Memory Block function (Int 31H Function 0100H).

Call With

AX = 0101H
DX = selector of block to be freed

Returns

if function successful
Carry flag = clear

if function unsuccessful
Carry flag = set
AX = error code

0007H memory control blocks damaged (also returned by DPMI 0.9 hosts).

0009H incorrect memory segment specified (also returned by DPMI 0.9 hosts).

8022H invalid selector

Notes

All descriptors allocated for the memory block are automatically freed by this function, and are no longer valid after this function returns.
Under DPMI 1.0 hosts, any segment registers which contain a selector being freed are zeroed by this function.
Refer to the rules for descriptor usage in Appendix D.

0007H	memory control blocks damaged (also returned by DPMI 0.9 hosts).
0009H	incorrect memory segment specified (also returned by DPMI 0.9 hosts).
8022H	invalid selector