
  You can have up to two serial ports on your I/O Card.  These
  serial ports support asychronous communication functions.
  And, these ports can be set to COM1, COM2, COM3 or COM4.

  The current release of PC or MS DOS recognizes COM1 and COM2.
  Therefore, the current PC DOS (MS- DOS) only performs I/O
  functions COM1 and COM2.  Unfortunately, DOS can not recoginze
  COM3 or COM4;i.e., input and output operations can not be
  performed by using COM3 or COM4.

  Two new serial port utilities enable COM3 and COM4 to perform
  the same functions as COM1 and COM2.  One is DEVCOM.SYS, a driver.
  The other is CMODE.COM, a utility program.


  1.   DEVCOM

       DEVCOM is a device driver that initializes two devices,
       COM3 and COM4, for serial ports on your I/O Card.  After
       DEVCOM has been executed, you can gain access to these
       serial ports by simply entering the names COM3 and COM4.

       Before starting DEVCOM, please set your I/O Card's serial
       ports to COM3 and COM4.  If the system fails to set these
       COM ports, the following message will appear on the screen:

       Can not find device COM n

       To execute DEVCOM, you must copy the DEVCOM utility onto
       your current working drive or DOS diskette.  The utility is
       entitled, DEVCOM.SYS.  This device driver sets the COM
       parameters into the memory reserved for the operating system's
       data and gives you the interface between DOS and BIOS.  The
       DEVCOM.SYS utility must be set into your CONFIG.SYS device.
       If your boot diskette or current working drive has a
       CONFIG.SYS device, please add the following command:

          DEVICE = DEVCOM.SYS

       If your boot diskette or current working drive does not have
       a CONFIG.SYS device, create one which includes the previous
       command.

       With your amended current working DOS diskette in the current
       working driver, reset the system.  You can reset the system by
       pressing the RESET buttom; simultaneously pressing CTRL, ALT
       and DEL; or turning the power off and on.  If COM3 or COM4 ports
       exist, then the following messages will appear on the screen:

          Device COM3 is installed.
          Parameters set to 2400, n, 8, 1
          Device COM4 is installed.
          Parameters set to 2400, n, 8, 1

       NOTE: A DEVCOM DEFAULT SETS COM3 AND COM4 COMMUNICATION
             PARAMETERS TO BAUD RATE 2400, NO PARITY, 8 DATA BITS
             AND 1 STOP BIT.

       If COM3 and COM4 ports do not exist, then the following
       messages will appear on the screen:

          Can not find device COM3.
          Can not find device COM4.

       NOTE: WHEN USING PC/MS DOS VERSION 3.3+, THE DEVICE DRIVER ALONE IS
             SUFFICIENT AND THE DOS MODE COMMAND CAN BE USED TO SET ALL THE
             SERIAL PORT OPTIONS AS NORMAL, EXCEPT A BAUD RATE OF 19,200.
             HOWEVER A 19,200 BAUD RATE CAN BE SET USING THE CMODE.COM.


  2.   CMODE COMMAND

       The utility programm, CMODE.COM, sets options for an
       asynchronous communications adapter.  The CMODE.COM also
       enables printer output to be routed to an asynchronous
       communications adapter or to another printer port.


  2.1  Setting Parameters

       The command format for setting the options of an asynchronous
       communications adapter is listed below.

          CMODE COMn:baud[,parity[,data bits[,stop bits[,p]]]]

       The variable "n" can be 1, 2, 3 or 4 designating the number
       of the asynchronous communications adapter.

       The protocol parameters used to initialize the asynchronous
       communications adapter can be set by replacing the "[" symbols
       with specific characters.  These parameters and the specific
       characters are listed below.

          Baud Rate: Enter 50, 75, 110, 134.5, 150, 300, 600, 1200,
                     1800, 2000, 2400, 3600, 4800, 7200, 9600, or 19200.

                     The default setting is 2400.

       NOTE: ONLY THE FIRST TWO CHARACTERS ARE REQUIRED, SUBSEQUENT
             CHARACTERS ARE IGNORED.  FOR EXAMPLE, IF THE COMMAND
             FORMAT WAS "CMODE COM3: 13,7", THE MODE OF OPERATION
             WOULD BE 134.5 BAUD RATE, EVEN PARITY AND STOPBIT
             PARAMETERS WOULD DEFAULT SINCE NO CHARACTERS WERE ENTERED.

          Parity:         Enter N (None), O (Odd), E (Even), M (Mark),
                          or S (Space).

                          The default setting is E.

          Databits:       Enter 5, 6, 7 or 8.

                          The default setting is 7.

          Stopbits:       Enter either 1 or 2.

                          The default setting is 2 if the baud rate
                          is less than or equal to 110.

                          The default setting is 1 if the baud rate
                          is greater than 110.

       The "P" option indicates that the asynchronous adapter is
       being used for a serial interface printer.  If you enter the
       "P", time-out errors are continously retried.  You can stop
       the retry loop by pressing Ctrl-Break.  To stop the time-out
       errors from being continously retried when you have entered
       "P", you must reinitialize the asynchronous adapter without
       entering the "P".


  2.2  Routing Printer Output

       The command formats for directing parllel printer output to
       an asynchronous communications adapter or to another printer
       are listed below.

          CMODE LPT#: = COMn

          CMODE LPT#: = LPT$

       There are three variables in this command format.  The variable
       "#" can be 1, 2, or 3 designating the printer port number.  The
       variable "n" can be 1, 2, 3 or 4 designating the asynchronous
       communications adapter.  And, the variable "$" can be 1, 2, or
       3 designating another printer port.

       All output direct to the printer LPT# is redirected to the
       asynchronous adapter n, or to another printer $.  Another format,
       CMODE LPT#: =LPT#, disables any redirection to the printer
       designated by the "#".

       Before you can use the CMODE to redirect the parallel printer
       output to a serial device, you must initialize the asynchronous
       communications adapter by using the CMODE COMn format described
       in Section 2.1 Setting Parameters.  If that serial device is a
       printer, your seial initialization command should also include
       the "P" parameter.


       NOTE: WHEN USED IN THE CMODE COMn FORMAT WITH THE "P" OPTION, OR
             IN THE CMODE LPT#: = COMn OR CMODE LPT#: = LPT$, THE CMODE
             COMMAND CAUSES THE PRINTER AND ASYNCHRONOUS COMMUNICATIONS
             ADAPTER INTERCEPT CODE TO BE MADE RESIDENT IN MEMORY.

