PDP-11 architecture Was: internet blocking problem ?

ben bfranchuk at jetnet.ab.ca
Fri Sep 11 13:47:40 CDT 2015

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

> 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

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