Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue

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From	Hans-Peter Diettrich <DrDiettrich1@aol.com>
Newsgroups	comp.lang.pascal.delphi.misc
Subject	Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue
Date	Fri, 19 Aug 2016 12:27:25 +0200
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P E Schoen schrieb:
> I have an application that uses a serial port component to read and 
> write data through a USB serial port at 57.6 kb. Originally I used the 
> SerialNG component and with some tweaking I was able to get it to work 
> reliably. But it has problems with Win10, so I changed the code to use 
> ComDrv32, which works when used in a simple TTY demo.

I don't remember what prevented programs from using the asynchronous I/O 
API. 57kbd also doesn't look like a dangerous transmission speed.


> I had to use a separate PChar pointer RecdPtr, and I also had to use an 
> integer for the pointer arithmetic. Apparently Delphi does not allow 
> RecdPtr := RecdPtr + (DataSize - (MAXCOMM-CommBufferPtr) ); RecdPtr + n 
> is OK. I'm not sure if I could just advance the DataPtr in the same way, 
> since it is declared as a generic Pointer type.

Delphi allows pointer math only with PCHAR. At least I'd use Cardinal 
instead of Integer, in a workaround.

DoDi

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Delphi D4: using pointers to transfer data from COMM queue to circular queue "P E Schoen" <paul@pstech-inc.com> - 2016-08-19 02:19 -0400
  Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue "P E Schoen" <paul@pstech-inc.com> - 2016-08-19 03:58 -0400
    Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue "P E Schoen" <paul@pstech-inc.com> - 2016-08-19 04:42 -0400
      Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2016-08-19 12:34 +0200
    Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2016-08-19 12:30 +0200
      Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue "P E Schoen" <paul@pstech-inc.com> - 2016-08-19 20:54 -0400
        Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2016-08-20 12:43 +0200
          Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue "P E Schoen" <paul@pstech-inc.com> - 2016-08-20 19:15 -0400
            Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2016-08-21 12:50 +0200
              Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue "P E Schoen" <paul@pstech-inc.com> - 2016-08-22 07:12 -0400
  Re: Delphi D4: using pointers to transfer data from COMM queue to circular queue Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2016-08-19 12:27 +0200

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