; Actual program loading.  Use the DOS interrupt.
        mov ax, 4B01h           ; load program
        mov dx, DTA             ; offset of file to load
        mov bx, execblk         ; parameter block
        int 21h                 ; load it
        jc ll16                 ; if error
        mov ax, sp
        sub ax, [SPSAV]
        cmp ax, 80h
        jb ll15                 ; if in range
        mov ax, 80h
ll15:
        mov word [spadjust], ax
        les si, [execblk.sssp]
        es lodsw                ; recover ax
        mov word [reg_eax], ax
        mov word [reg_esp], si
        mov word [reg_ss], es
        les si, [execblk.csip]
        mov word [reg_eip], si
        mov word [reg_cs], es
        push ss
        pop es
        call getpsp
        xchg ax, bx             ; ax = PSP, clobber bx
        mov word [pspdbe], ax
        clropt [internalflags], attachedterm
        mov di, reg_ds
        stosw
        scasw
        stosw                   ; reg_es
        push ax
        call setpspdbg

                ; Finish up. Set termination address.
        mov ax, 2522h           ; set interrupt vector 22h
        mov dx, int22           ; ds => lDEBUG_DATA_ENTRY
        int 21h
        pop ds
        mov word [TPIV], dx
        mov word [TPIV+2], ss   ; => lDEBUG_DATA_ENTRY
        push ss
        pop ds