================================================================================
                     Gravis Ultrasound Mixer (for OS/2 2.x)
                             Freeware, Version 1.1

                            (c) 1994, Robert Turner
                      rdturner@undergrad.math.uwaterloo.ca
================================================================================

DESCRIPTION:

      This is a simple line mixer for the Gravis Ultrasound.  It allows the
user to enable and disable the input and output lines on their Ultrasound 
card. It requires OS/2 2.x (with Presentation Manager installed) to run.

This product is intended to hold over until an MMPM mixer for the Ultrasound
arrives.

This software is *FREE*.  The author can be contacted at the above Internet
electronic mail address for at least the next year.  Comments, bug reports, 
and suggestions are all welcome.

I hope this proves useful to someone other than myself.


DISCLAIMER: (Just in case someone thinks about sueing me for something...)

      THE AUTHOR (ROBERT TURNER) PROVIDES NO GUARRENTEE THAT THIS SOFTWARE
WILL PERFORM AS DESCRIBED, ALTHOUGH EVERY ATTEMPT HAS BEEN MADE TO ENSURE 
THAT IS DOES.  THE AUTHOR ALSO WARNS THAT IMPROPER USE OF THIS SOFTWARE, 
CAUSED BY SETTING UP THE OPTIONS INCORRECTLY, OR BY HAVING INCOMPATIBLE 
HARDWARE, MAY CAUSE MALFUNCTIONS, AND POSSIBLY DAMAGE (ALTHOUGH HE HOPES 
NOT) TO THE USER'S HARDWARE.  BY USING THIS SOFTWARE, IT IS UNDERSTOOD 
THAT THE USER UNDERSTANDS THAT HE/SHE UNDERTAKES COMPLETE RESPONSABILITY 
FOR WHATEVER HAPPENS THROUGH USE OF THIS SOFTWARE, BE IT BENEFICIAL OR 
DETREMENTARY.


INSTALLATION:

      Copy the GUSMixer.EXE file into a directory or your choice.  You may 
want to put it in a directory on your path.  You can add it to your startup 
folder or your CONFIG.SYS file so that is gets run every time you start 
your system.

      Before playing with the line settings, select "Options..." from the 
system menu of the GUSMixer window, and make sure that the "Port" setting 
corresponds to the I/O port where your Ultrasound card is located.


USAGE:

      The program is fairly self explanatory.  The main window contains 
three check boxes which correspond to the outputs and inputs on the back of 
the Ultrasound card.

     "Line Out"     When checked, enables output to the line out jack, and 
                    the headphone out jack.
     "Line In"      When checked, enables input to the Ultrasound from the
                    line in input.
     "Mic. In"      When checked, enables input to the Ultrasound from the 
                    Microphone input.

The check boxes can be in three states.  Normally you will only see the two 
determinate states, checked and unchecked.  These correspond to the lines 
being enabled and disabled respectively.  The other state is the grayed sate 
for the check box.  This indicates the GUSMixer does not know what state the 
line is in.  (NOTE: The Ultrasound does not allow querying of the line states, 
so until you set them to something, they will be indeterminate.)

      Two extra menu items are attached to the system menu, 'Options..." and
"Product Information...".


OPTIONS

      Restore Window Position on Startup

          If this option is set, when GUSMixer starts, it will restore the 
          window to the last saved position.  If the window was minimized, 
          this state will be preserved.  The window position is saved when 
          you press "Save Now", or if "Save Options on Exit" is set, when 
          GUSMixer terminates.

      Save Options on Exit

          If this option is set, the options displayed in this window will be 
          saved.  Options are saved in the OS2.INI file.

      Port

          This specifies the I/O port where your Ultrasound is located.  
          Currently GUSMixer does not attempt to locate the Ultrasound, and 
          hence requires the user to set this variable.  The default is 0x220.
          The user should ensure that this is set up correctly before trying 
          to change the line settings.

      Set Lines on Startup

          If this option is set, when GUSMixer starts, it will set the 
          Ultrasound input/output lines to reflect the "Initial Line 
          Settings".

        Initial Line Settings            
          Line Out      \
          Line In        >  These are the same as in the main window.  Except
          Mic. In       /   that you cannot leave the line in an indeterminate 
                            state.

      Refresh Lines

          If this option is on, GUSMixer will refresh the Ultrasounds lines
          periodically to the current state shown by the main window.  The
          refresh interval is specified by the "Refresh Interval" field.

        Refresh Interval

          Specifies the refresh interval in tenths (1/10) of a second.


      Save now

          Saves the current settings.  Useful if you don't want to save 
          settings every time you close GUSMixer (or shut down you system 
          with it running).


COMMAND LINE OPTIONS

     The command line options always override the saved settings.  So if 
you've got the port saved wrong, or you're having problems, you can use 
these to force a known state.  All options must be specified separately 
(sorry...), ie.
    -l -o -i -s  
instead of
    -lois
If any parameters are invalid, they are ignored and no error is reported.
Parameters may be specified in any order.  Parameters are processed in the
order they are specified, and the last occurance of the parameter is the one
that takes effect.  The parameters all correspond (with the exception of 
"-i") to options in the "Options" window.

     -pNNNNN     Port:      Replace NNNNN with the port number, valid 
                            choices are: 
                              0x210, 0x220, 0x230, 0x240, 0x250, 0x260.

     -fNNNNN     Refresh:   Replace NNNNN with the desired refresh interval
                            (in tenths (1/10) of a second). If 0 is 
                            specified, the refreshing of the lines is 
                            disabled.

     -o[0|1]     Line Out:  Enables ("1") or disables ("0") the line out.  
                            Defaults to enable if "0" or "1" not specified.  
                            Note that for the line to actually be enabled 
                            or disables, the "-s" option must also be 
                            specified.

     -l[0|1]     Line In:   Enables ("1") or disables ("0") the line in.  
                            Defaults to enable if "0" or "1" not specified.  
                            Note that for the line to actually be enabled or 
                            disables, the "-s" option must also be specified.

     -m[0|1]     Mic. In:   Enables ("1") or disables ("0") the microphone 
                            in.  Defaults to enable if "0" or "1" not 
                            specified.  Note that for the line to actually 
                            be enabled or disables, the "-s" option must 
                            also be specified.

     -i[0|1]     Iconic:    Minimizes ("1") or Restores ("0") the window.  
                            Defaults to Minimize if "0" or "1" not 
                            specified.  Note that the "-r" option must be 
                            specified for this option to take effect.

     -r[0|1]     Restore:   Restores the window settings to the saved or 
                            overridden ones.

     -s[0|1]     Set Lines: Sets the Ultrasound input and output lines to the
                            saved or overidden settings.


OTHER PEOPLES TRADEMARKS AND COPYRIGHTS

(These are not quite exact, but are intended to give an idea who owns what.)

     Gravis, and Gravis Ultrasound are either registered trademarks, or 
     copyrighted names of Advanced Gravis or Forte.
     All rights reserved.

     OS/2 and Presentation Manager are either registered trademarks, or
     copyrighted names of International Buisiness Machines Corp.
     All rights reserved.
