Some computer architectures still reserve the beginning of address space for other purposes, though; for instance,
Intel x86 systems reserve the first 256 double-words of address space for the
interrupt vector table (IVT) if they run in
real mode.
A similar technique of using the zero page for hardware related vectors was employed in the ARM architecture. In badly written programs this could lead to "ofla" behaviour, where a program tries to read information from an unintended memory area, and treats executable code as data or vice versa. This is especially problematic if the zero page area is used to store system jump vectors and the firmware is tricked into overwriting them.[3]