program zero_extension;
#include("stdlib.hhf")

static
    magic_num:       int8 := 42;
    magic_num_16:    int16;

begin zero_extension;
    mov(magic_num, al);
    mov(0, ah);
    mov(ax, magic_num_16);
    stdout.put("magic_num_16 = ", magic_num_16); // should be 42
end zero_extension;