Re: Port LPT + ADA (whta do I wrong?)

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Sat, 4 Dec 2004 19:05:44 +0100, S�awo - MIR wrote:

> Maybe someone tell me what do I wrong (??), or maybe everything is wrong ;-)

Only Hungarian notation is wrong! (:-))

> These are the fragments of my code:
> 
> Variables:
> 
> hLPT : Win32.Winnt.HANDLE;
> struktura : Win32.Winbase.LPOVERLAPPED;
                                  ^^^^^^^^^^^^^^
                                  This is a pointer!
I presume (depending on the Win32 bindings, you are using) it should be:

struktura : aliased Win32.Winbase.OVERLAPPED;

> read : aliased DWORD;
> 
> type LPT1_Bajt is record
>         Busy : boolean;
>         ACK : boolean;
>         Paper : boolean;
>         Sel : boolean;
>         Error : boolean;
>         Trzy_z : boolean;
> end record;
> 
> for LPT1_Bajt use record
>         Busy at 0 range 7..7;       --pin 11 (zanegowany)
>         ACK at 0 range 6..6;        --pin 10
>         Paper at 0 range 5..5;      --pin 12
>         Sel at 0 range 4..4;        --pim 13
>         Error at 0 range 3..3;      --pin 15
>         Trzy_z at 0 range 0..2;     --trzy zera na poczatku
> end record;
> 
> Reading from LPT Port:
> 
> st : aliased LPT1_Bajt;
> 
> struktura.OffsetHigh := 16#379#;
>
> !!!! In this place (after compiling, building and runnig it) appears an
> error: "CONSTRAINT_ERROR access check failed" !!!!

Yes, because structura = null
 
> if Win32.Winbase.Readfile(hLPT, st'address, Dword(1), read'access,
> struktura) =

That should be structura'Access, accordingly.

> Win32.False then
>      Put_Line ("Nie udalo sie odpalic LPT");
>      raise LPT_Error;
> end if;
> 
> Opening LPT port:
> 
> hLPT := Win32.Winbase.CreateFile ( CP ("LPT1" & ASCII.Nul),
>                                    Win32.Winnt.GENERIC_READ,
>                                    0,
>                                    null,
>                                    Win32.Winbase.OPEN_EXISTING,
>                                    Win32.Winbase.FILE_FLAG_OVERLAPPED,
>                                    System.Null_Address);


-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de