[Simh] Compatibility you can use Was: VAX/VMS

[Johnny Billquist]

On 2016-02-22 10:48, lists at openmailbox.org wrote:
> On Mon, 22 Feb 2016 10:07:10 +0100
> Johnny Billquist <bqt at softjar.se> wrote:
>
>> On 2016-02-22 07:07, lists at openmailbox.org wrote:
>>> However, we see that Intel's hardware compatability is only of academic
>>> interest because virtually none of the OS or apps for several
>>> generations of Intel chips runs on any remotely current Intel-hosted
>>> OS. I already pointed out many day-to-day incompatibilities between
>>> code running 32 bit vs. 64 etc. on Intel today. You can blame Microsoft
>>> or Bell Labs or even Richard Stallman but Intel has certainly been
>>> involved intimately with much OS development on its platform and has
>>> continued to bork time after time.
>>
>> You can't seriously mean that you think that a 32-bit application and a
>> 64-bit application would be expected to be compatible with each other?
>> I would expect the 32-bit code to work in 32-bit mode, but having it
>> work if you are in 64-bit mode is a ridiculous expectation.
>
> Really? It works fine on IBM's z/OS.

Yes. And now you are talking about the OS, which manages parts of this.

> It seems ridiculous to me that you think it shouldn't. This is what I have
> been saying. IBM moved from 24 bit to 31 bit to 64 bit and everything still
> works. No expanded footprint, no duplicate libraries, no problem.

There is no reason it couldn't work.

>> And the OS should detect that it's a 32-bit application, and set the
>> system up for running such an application with the CPU set the right way.
>> The CPU can do it. If things fail because the OS does things wrong, you
>> should not blame the CPU.
>
> I didn't blame the CPU. I said Intel's compatibility is really only
> academic and has no actual value in most cases:

You did blame the CPU. You have been saying time and again that Intel 
don't manage backward compatibility. Intel only do the CPU. So if you 
blame Intel, it's only the CPU you can mean.

>>> We all know at the end of the day people buy hardware to run apps. We
>>> also know most of the apps ever written for Intel are no longer useful
>>> even if you could boot obsolete OS and run them. Any meaningful notion
>>> of compatibility has to include the ability to continue to run your
>>> apps on every new OS and hardware generation. With Intel you can't. You
>>> can point all the fingers you want but that is the reality in the Intel
>>> environment.
>>>
>>> In practice, several decades of software and development investment,
>>> applications, and OS go up in smoke with each new generation of Intel
>>> chips. In contrast IBM has preserved the customer's investments in
>>> technology, development, and applications. IBM takes the loss on the OS
>>> development but the customer's applications continue to run forever on
>>> the latest platform. Intel is an ecosystem of churning, turmoil and
>>> waste. That's something only an accountant could love.
>>
>> I think you are confusing the backware compatibility in the processor,
>> which is working just fine, with the less than stellar backward
>> compatibility in various OSes along the way, which is nothing you should
>> blame on Intel.
>
> I'm comparing Intel's shortcomings and consistent track record of borks to
> what I have seen done well by IBM. It was all there for Intel and the
> developers who write for it to see how things were done right, but they
> kept making mistakes. There's just no excuse for most of the decisions.
> Except possibly from Intel's accounting viewpoint as was discussed.

And here we go again. You point the finger at Intel, while in truth the 
CPU can do the work just fine. And you compare with IBM, and more 
specifically what their OS handles, which is not meaningful to compare 
to what Intel is doing, as Intel is not doing OSes.

>> Like I said, grab an old DOS floppy, pop it into a a new machine, and it
>> will boot. That's a fact.
>
> See above. That doesn't really help the 99.9 bar percent of people that
> spent money on DOS and DOS apps and countless other OS and software that
> don't run on Windows on modern hardware.

No. But you can boot your DOS on the modern hardware, and still run the 
software. The backward compatibility in the hardware is there. I have no 
problems with you complaining that Microsoft sucks. I also have no 
issues with complaints that Intel made a horrible CPU. But it's stupid 
to say they don't manage backward compatibility, when it is so obvious 
that they do.

	Johnny