slow COM1 port after clean install of XP Home RRS feed

  • Question

  • WIndows XP Service Pack 3 forum,

     I recently had to do a clean install of Windows XP Home SP3.

     Every thing works except when I use COM1 port download
     a program to a pic microcontroller it consumes 100% of
     the CPU time and runs real slow.

     This all worked properly before the install.

     The COM1 port settings are:
     Bits per second:  9600
           Data bits: 8
              Parity: None
           Stop bits: 1
        FLow control: None

     Everything in my Hardware Device Manager looks OK except
     there is a yellow question mark next to:
      Base System Device and PCI Modem.

     Any suggestions?

     Thanks for any replies,
    Saturday, April 9, 2011 4:08 PM

All replies

  • Windows XP forum,

     Solved the slow COM1 port problem.

     The application I use to program my pic device through
     COM1 port, ic-prog, can run in 1 of 2 interface modes,
     Direct I/O or Windows API mode.  The setup instructions on
     the internet all recommend Windows API mode.  I had forgotten
     that my programming board allows me to run in Direct I/O mode
     which is much faster.


    Sunday, April 10, 2011 2:09 AM