I don't know about the PDP but the VAX allowed access to address zero. Even more insidious, it allowed you to dereference a null pointer and guaranteed it would contain a zero, which resulted in many tiresome portability issues - I used Interdatas at the time, which faulted on a read at address zero.
-Steve > On 26 Nov 2015, at 17:48, Bakul Shah <ba...@bitblocks.com> wrote: > > Good points! Though 0 was a valid address on pdp11, right?
