BETA RELEASE OF OS/2 COMMUNICATION DRIVERS


 COM.SYS       08-10-92
 VCOM.SYS      08-07-92
 COMM.DRV      06-11-92
 MODE.COM      08-06-92


 IBM DISCLAIMS ALL WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING
 WITHOUT LIMITATION, WARRANTIES OF FITNESS AND MERCHANTABILITY WITH
 RESPECT TO THE INFORMATION IN THIS DOCUMENT AND INCLUDED SOFTWARE
 PRODUCTS.  . BY FURNISHING THIS MATERIAL, IBM GRANTS NO LICENSES TO ANY
 RELATED PATENTS OR COPYRIGHTS.

 Copyright IBM Corporation, 1992, all rights reserved.


 1.0       INSTALLATION PROCEDURE

              a.    The following files will be replaced:

                    x:\OS2\COM.SYS
                    x:\OS2\MODE.COM
                    x:\OS2\MDOS\VCOM.SYS
                    x:\OS2\MDOS\WINOS2\SYSTEM\COMM.DRV

              These files will be backed up with the extension *.392.  If 
              files with this extension already exist, then NO BACKUP will 
              take place.  The installation utility is assuming that you 
              are using IBM OS/2 2.0 GA release drivers.  

              b.    Switch to the drive and directory where the BETA files 
                    are located.

              c.    Enter "cominst  x:" at the command line where
                    x: is the drive letter of the OS/2 Partition.

              d.    To DE-Install the BETA drivers communication driver, 
                    Enter DEINSTL x: where x: is the drive letter of the
                    OS/2 Partition.

    2.0      DESCRIPTION OF DRIVERS

             The following is a brief description of the BETA
             communication drivers for OS/2 2.0.  There are new
             parameters for the COM.SYS which is located in the
             CONFIG.SYS file.

    2.1      COM.SYS

             COM.SYS now has new parameters to indicate the COM port
             number, the I/O address, the UNIQUE IRQ level and  how to
             handle spurious interrupts.   An example follows:

             DEVICE=C:\OS2\COM.SYS (n,xxxx,ii,s) [(n,xxxx,ii,s)]...


             where the last parameter is optional.

             n       :   COM port number (usually 3 and 4 but it is
                         possible to configure any communication port to a
                         differrent IRQ or I/O Address

             xxxx    :   COM port address

             ii      :   IRQ level

             s       :    Spurious interrupt handling switch
                          values:

                          D or d   to deinstall COM driver if
                                   more than 1000 consecutive
                                   spurious interrupts occur.

                          I or i   to ignore spurious interrupt.

                          P or p   to post error if more than 1000
                                   consecutive interrupts occur.   When 
                                   posting an error, some DOS applications 
                                   can hang.

             NOTE    :   Some UART chips or malfunctioning modems can cause 
                         interrupts when no interrupt is expected.  These
                         interrupts are known as spurious interrupts.


             COM.SYS also has the following fixes:

             1. COM.SYS now uses a different algorithm to test for the
                presence of a communications port at the given address.  
                There were certain cases where a port was not recognized.

             2. COM.SYS does not detect Hayes ESP card so that Hayes
                ESP card can be used as a regular dual asynch card.


    2.2      VCOM.SYS

             No parameters or settings required.  This version of VCOM.SYS 
             should work better with X00.SYS (and other similar
             applications) when COM_DIRECT_ACCESS is ON.  COMDD.SYS (which 
             is required by older DOS applications such as BASIC) should 
             also perform better.  COMMDD.SYS is loaded into the DOS_DEVICE 
             setting for a Virtual Dos Machine.  


    2.2.1    COM_DIRECT_ACCESS DOS property

             When COM_DIRECT_ACCESS is ON, VCOM.SYS will allow a DOS 
             application to access the communication ports directly.  This 
             DOS property makes LapLink III, FaskLynx, FSDUAT, AS/400 
             Asynch Router, MS WORD work in VDM session.  However, since 
             the buffers in COM.SYS cannot be used, characters may be lost 
             and and some applications may suffer from the lack of 
             buffering.  With most DOS applications, COM_DIRECT_ACCESS 
             should be set to OFF as its default setting.  


    2.2.2    COM_SELECT DOS Property

             COM_SELECT allows the DOS session to select only one 
             communication port to be used by the session.  The 
             communication ports which are not selected will be hidden from 
             the DOS session.  There are some DOS applications which take 
             over every available communication port.  This DOS property is 
             effective in preventing those DOS applications from taking 
             over all the communication ports.  An example of a DOS            
             application which attempts to control all the communcication 
             ports is LapLink Pro.  If LapLink Pro and another application 
             which accesses a communication port are executed at the same 
             time, it is necessary to set COM_SELECT.  The default setting 
             is ALL.


    2.3      COMM.DRV

             COMM.DRV contains the support for COM3 and COM4 in WinOS2.  
             This COMM.DRV requires the new VCOM.SYS.