Re: Low level (GNAT) Ada?

[Stephen Leake <Stephen.Leake@gsfc.nasa.gov>]

Matthew Kennedy wrote:
> 
> Hello all,
> 
> I'm using GNAT for Windows (actually NT 4 in my case).
> 
> I'd like to be able to control some purpose-built devices on the
> parallel and serial ports of my PC as well as bus cards. I have searched
> hard through the documentation for a library that provides
> parallel/serial interfaces but they just don't exist. I haven't even
> found basic C-like outb/inb functions.
> 
> Everybody keeps saying that Ada is also great for system and low level
> programming but it doesn't look like it from the Windows GNAT point of
> view.

The "library" you are looking for is the Win32 API, provided by
Microsoft as the operating system. The OS owns the ports; you cannot
write to them directly. You need to get the Microsoft System Development
Kit (comes with the Aonix compiler; also comes with Microsoft
compilers), and read the Help file.

You need an Ada binding for the Win32 API; Win32Ada is free; Aonix sells
another (more structured?) one; RR sells a thick binding (see
www.adahome.com for sources).

To access the serial ports, you just open a file named COM1, COM2, etc.
I have not looked into writing to the parallel port; since it is named
LPT1 in DOS, you can probably get to it that way. 

> 
> BTW, does anyone know if it is possible to interface to the Windows DDE
> via a GNAT package and vice-versa?

Again, the Win32 API provides functions for doing DDE; you need the Ada
binding to those functions. I'm not sure if they are included in
Win32Ada.
> 
> --
> Matthew Kennedy
> Student of Electrical and Electronics Engineering
> University of Southern Queensland, Australia

-- 
- Stephe