Portability and the Ivory Tower (was Re: Book on Microsoft C)

[Leslie Mikesell]

In article <425bf40d.b11a at falcon.engin.umich.edu> ejd at caen.engin.umich.edu (Edward J Driscoll) writes:

>Your point is certainly worth taking into consideration.  My
>reply question would be:  Are you willing to stick with
>teletype compatibility forever?

I don't see how anyone who uses news can avoid understanding the
generality of plain-text applications.  If these messages had
any particular hardware dependence, most of us wouldn't see them. 
That's not going to change anytime soon.

>You also left out the option of changing the code to
>exploit the new hardware.

If you own the code and have the resources to rewrite it, then fine,
but otherwise it would be foolish to bet your company that someone
else is going to do it in time to keep you in business if you outgrow
your current equipment.

>If applications do not take
>advantage of the features of the hardware, then why pay
>for that hardware? 

For some purposes, you need state of the art equipment that goes beyond
current standards - perhaps graphics or engineering work where the
special features pay for themselves without regard for anything else.
I certainly can't see anything about your message to indicate that
it came from any special kind of machine...  

>You seem to be claiming that it is
>important for software to be backwards-compatible, but
>not for hardware.  If the software outlasts the hardware
>by a factor of three, I would think the reverse would be
>true.

I meant that software should take portability into consideration to
avoid the need to make backwards-compatible hardware later.  Look
at the market that IBM has locked up as long as people run
programs written for the 370 which the current machines still
emulate - and that is just for fill-out-the-form functionality.

>[PS:  We seem to be drifting a little from C.  Should
>we move this over to the software engineering newsgroup?]

Portability is one of the reasons for choosing the C language
so perhaps the discussion is appropriate.  Certainly any program
being written now will likely be run in a very different environment
within a few years. With the increasing use of networking, it is
desirable to be able to run a program on one machine but display
the output on another.  This will obviously require paying attention
to some standards.

Les Mikesell