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 <mailto:bakul@bitblocks.com>> wrote:
> 
>> Good points! Though 0 was a valid address on pdp11, right? 
>>>>>>