keyboard polling in ADA

keyboard polling in ADA

[Matthew S Low]

Our software engineering class is attempting to write an ADA program that
requires keyboard polling. In other words, we want to enter a loop and
continue that loop until the user presses any key on the keyboard. This
sounds like a fairly easy process to implement, but a very difficult one to
find info on. Any info or hints on how to achieve keyboard polling using ADA
would be greatly appreciated.  Thanks.

Matt Low
(mlow@galaxy.calpoly.edu)

Re: keyboard polling in ADA

[David Arno]

In article <3jlo93$4pv@galaxy.csc.calpoly.edu>
           mlow@galaxy.csc.calpoly.edu "Matthew S Low" writes:

> Our software engineering class is attempting to write an ADA program that
> requires keyboard polling. In other words, we want to enter a loop and
> continue that loop until the user presses any key on the keyboard. This
> sounds like a fairly easy process to implement, but a very difficult one to
> find info on. Any info or hints on how to achieve keyboard polling using ADA
> would be greatly appreciated.  Thanks.
> 
> Matt Low
> (mlow@galaxy.calpoly.edu)
> 
> 
> 

Perhaps if you specified what computer you are attempting to do this on, you
might get some help from ppl.
-- 
David Arno

keyboard polling in ADA

[Matthew S Low]

I'm sorry, in my last posting for keyboard polling in Ada I forgot to
mention that I am attempting to do this using BSD UNIX. I was also asked
whether I was trying to "do something" while the program looped waiting for
a keystroke, and the answer is yes. I'm beginning to look into the areas of
interrupts and forking tasks in ADA. Any help or suggestions would be
greatly appreciated. 

Matt
(mlow@galaxy.calpoly.edu)

Re: keyboard polling in ADA

[David Wheeler]

Matthew S Low (mlow@galaxy.csc.calpoly.edu) wrote:

: I'm sorry, in my last posting for keyboard polling in Ada I forgot to
: mention that I am attempting to do this using BSD UNIX. I was also asked
: whether I was trying to "do something" while the program looped waiting for
: a keystroke, and the answer is yes. I'm beginning to look into the areas of
: interrupts and forking tasks in ADA. Any help or suggestions would be
: greatly appreciated. 

There are at least 3 ways I can think of:

1. Use a pragma Convention(...) and call the operating system, presuming
   that the OS provides a way to poll the keyboard.
   This is usually easy.
2. Use Ada 95, which has a way to poll the keyboard in Text_IO.
3. Use Ada tasks to implement this.
   For an example, see the "PDI" example at:
        http://lglwww.epfl.ch/Ada/Examples/PDI/


This sort of stuff depends on the Ada implementation & OS interface.
   


--- David A. Wheeler
Net address: wheeler@ida.org

Re: keyboard polling in ADA

[Robert Dewar]

David Wheeler said

"1. Use a pragma Convention(...) and call the operating system, presuming
   that the OS provides a way to poll the keyboard.
   This is usually easy."

He meant pragma Import, pragma Convention won't get you very far in calling
an operating system service routine!