[Info-vax] For sale: VAXstation 4000/90 128MB Fully Working and Tested

[Bill Gunshannon]

On 7/1/22 20:56, Arne Vajhøj wrote:
> On 7/1/2022 6:50 PM, Bill Gunshannon wrote:
>> On 7/1/22 16:02, Arne Vajhøj wrote:
>>> On 7/1/2022 2:31 PM, Bill Gunshannon wrote:
>>>> On 7/1/22 11:10, Arne Vajhøj wrote:
>>>>> On 7/1/2022 10:52 AM, Dave Froble wrote:
>>>>>> For some reason Arne, you seem to feel that that which isn't 
>>>>>> broken must regardless be fixed.  I just don't understand such.
>>>>>>
>>>>>> I do believe that I mentioned that the Codis application/ERP did 
>>>>>> what the users needed, is successfully running their businesses, 
>>>>>> and just about anything else would be a step down, not up.
>>>>>
>>>>> Progress is not about replacing things that are broken. Progress
>>>>> is about replacing things that work with something that work better.
>>>>>
>>>>> Horse wagons did not stop working. But trains, cars and airplanes non
>>>>> the less replaced them for transportation.
>>>>>
>>>>> Your Basic code running on PDP-11 did not stop working, 
>>>>
>>>> Actually, it did.  But not because of the code but because someone
>>>> decided to force the unneeded change by making the PDP-11 unobtanium!
>>>>
>>>>>                                                         but the
>>>>> new shiny VMS VAX thing was just better.
>>>>
>>>> Was it?  My guess is that the only improvement that might have been
>>>> needed for Dave's application was a faster processor.  And that was
>>>> done even after the death of the PDP-11 in DEC's eyes.
>>>
>>> I don't think PDP-11 not being available was the driver behind the
>>> move to VAX.
>>
>> Not lack of availability at first, but complete stoppage of development
>> played a major role.
> 
> I am not PDP-11 knowledgeable but per wikipedia the last models
> (93 and 94) was released in 1990 at the time when VAX was getting
> close to retirement.

And Mentec introduced at least one improved PDP-11 CPU but none of
them had any real new technology.  Just minor clock speed ups.  Not
what you were seeing in other processors where shrinks were resulting
in large speed ups.

> 
>>> PDP-11 production continue until 1997 when people were migrating
>>> from VAX to Alpha - not to VAX.
>>
>> How much development was done during that period?
> 
> Apparently some up to 1990. A decade after many did the move
> to VAX.

Not really development.  Just the same thing warmed over.

> 
>>                                                 How many shrinks
>> to increase speed?  How many new peripherals were made available?
>> We didn't even get decent network cards or even disk controllers for
>> things like SCSI except from third parties.  Trust me, people using
>> PDP-11's could see the writing on the wall.
> 
> Both end customers, ISV's and DEC could see the writing on
> the wall - 16 bit did not have a future.

And when they same customers saw the same for 32 bit?  Did Intel
throw out the X-86 architecture  or make it fit the 64 bit world?
Granted, Intel almost missed the boat and might have if AMD hadn't
come along.  Why could there not be a 32 bit PDP-11?  Why did they
need a totally new and totally incompatible processor?

> 
> Everybody (read: most) wanted first 32 bit and later 64 bit.
>

And I still don't see what part of the PDP-11 basic architecture
made them not be extensible to that.  The PDP-11 architecture was
by far one of the best I have worked with and my experience goes
all the way back to the 8080 and 6800.

bill