RS232 Code

Comments

• Sephiroth2

  January 2002

  : Greetings
  : I've been given the task of converting an antique QBasic program to C++(normal code) MSVC++ to be specific. The 3 lines that are giving me the most trouble are below the first one I've figured out and is working:
  : OPEN "com2:600,n,8,1,cd0,cs0,ds0,op0" FOR INPUT AS #3: CLOSE 3
  :
  : That took awhile, the next two have me completely baffled;
  : OUT &H288, 3
  : OUT &H288, 1
  :
  : How can I do that in C++, I'm not seeing any way of doing this on a single thread & that's what I gota use.
  :
  : Theres also this one:
  : INP(&H298)
  : It's writing to & reading from a com port thats connected to device 'x', I just can't find a C function that'll do that the way QBasic does. I'm also not that good with hardware code...
  :
  : I've been at this 13 hrs straight, any help would be appreciated.
  :
  : Thank You
  : Stoic Joker
  :
  The first one means:
  __asm {
  mov dx,648
  mov al,3
  out dx,al
  mov al,1
  out dx,al
  }
  And the other is:
  __asm {
  mov dx,664
  in al,dx
  }
  This will not work under Windows NT.
  On Windows NT, hardware is accessed through device drivers only.
  
• Stoic Joker

  January 2002

  : : Greetings
  : : I've been given the task of converting an antique QBasic program to C++(normal code) MSVC++ to be specific. The 3 lines that are giving me the most trouble are below the first one I've figured out and is working:
  : : OPEN "com2:600,n,8,1,cd0,cs0,ds0,op0" FOR INPUT AS #3: CLOSE 3
  : :
  : : That took awhile, the next two have me completely baffled;
  : : OUT &H288, 3
  : : OUT &H288, 1
  : :
  : : How can I do that in C++, I'm not seeing any way of doing this on a single thread & that's what I gota use.
  : :
  : : Theres also this one:
  : : INP(&H298)
  : : It's writing to & reading from a com port thats connected to device 'x', I just can't find a C function that'll do that the way QBasic does. I'm also not that good with hardware code...
  : :
  : : I've been at this 13 hrs straight, any help would be appreciated.
  : :
  : : Thank You
  : : Stoic Joker
  : :
  : The first one means:
  : __asm {
  : mov dx,648
  : mov al,3
  : out dx,al
  : mov al,1
  : out dx,al
  : }
  : And the other is:
  : __asm {
  : mov dx,664
  : in al,dx
  : }
  : This will not work under Windows NT.
  : On Windows NT, hardware is accessed through device drivers only.
  :
  
  Greetings
  And thank you for the reply, I'm not sure which OS the Program is supposed to run on, but I'm working on that code in WinXP.
  
  I ended up using CreateFile("COM2",...) and then using SetCommState(...) to configure the port. For the I/O I'm trying WriteFile(...) & ReadFile(...) & giving them a handle to the port, it seemed to work but I've no way to test it.
  
  Does that sound like I'm on the right track??? I can't read(understand) ASM, can you give me a C version of you answer, ...or is there one?
  
  Thank You
  Stoic Joker
  
• AsmGuru62

  January 2002

  Just FYI:
  
  OUT is outport() in C,
  IN is inport() C.
  
  If you are R/W bytes then use outportb()/inportb().
  Check your compiler manual.
  
  Now, if you in WindowsXP - use Comm API, of course, because
  the functions above are for DOS. They wotk in Windows too, but
  for serial communication - use the API:
  
  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/win32/catfunc_26m1.asp
  
  Click on 'Communication' link...