I did a port just like that (DTS Generic Unix) just to see what it would be like. It was awful. I’ll never do that again.

On Nov 26, 2015, at 6:14 PM, Steve Simon <steve@quintile.net> wrote:


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 <bakul@bitblocks.com> wrote:

Good points! Though 0 was a valid address on pdp11, right?