PDP-11 architecture Was: internet blocking problem ?

[ben]

On 9/11/2015 8:39 AM, Johnny Billquist wrote:
> On 2015-09-11 16:36, Noel Chiappa wrote:
>>      > From: Jon Elson elson
>>
>>      > I actually LIKED the PDP-11 architecture quite a LOT, but the
>> limited
>>      > memory was a big killer.
>>
>> The good thing about the PDP-11 was the 16-bit word size. (It resulted in
>> what's probably the most elegant architecture, in bang/buck terms, of all
>> time.) The bad thing about the PDP-11 was the 16-bit word size. (For the
>> reason you point out.)
>
> WHile I agree that the PDP-11 is a wonderful architecture, it really is
> a few bits short of perfect, both for addressing, and for opcode
> allocation.

NOW if the had made the PDP 11 - 18 bits I think we could have had a 
winner. It is the loss of two address bits that is the problem with 16
bits.

> The is obvious when you look at the EIS and FPP extensions, which could
> not retain the general instruction layout format because of a lack of bits.

Too bad we got the 8086 rather than PDP-11 style (simplified design?) 
for 8/16 bit CPU.

>      Johnny
>
Ben.