Patch 217 - VideoLogic GrafixStar 600 DOS refresh control utility
=================================================================

CONTROL.COM is a program which allows you to alter the refresh for various modes.  
This program is designed for DOS operation, and is not necessary in Windows 3.1, 
Windows 95 and OS/2 drivers due to their built in mechanisms for changing refresh 
rate control. The program is resident in memory and occupies 1,664 Kbytes of 
memory space.  At anytime, CONTROL.COM can be released from memory (see instruction 
below for more information).
 
*** Please note: This program is not suitable for use with a fixed frequency monitor.


Supported modes
===============

Refresh rates can be selected from the modes listed in the table below:-

Resolution	Colors
320x200		256	N/A	N/A
640x400		256	65k	16.7m
640x480		256	65k	16.7m
800x600		256	65k	16.7m
1024x768	256	65k	N/A
1152x864	256	65k	N/A
1280x1024	256	65k	N/A



Background
==========

In order to safely use the refresh rate program, it is vital that you know the 
following information with regards to your monitor.

The monitors maximum resolution capabilities
--------------------------------------------
Please use resolutions listed from the supported resolutions list above.  If 
your monitors maximum resolution capability does not match a resolution on the 
list, you must select the nearest mode below your monitors maximum capabilities.  
eg. For a monitor with a max resolution of 1152x1024, you would select 1152x864.

Maximum Horizontal scan rate
----------------------------
This describes the rate in which the monitor can display pixels on a line.  
Otherwise known as the line rate.  This is typically measured in units of thousands 
of Hertz (kHz).

Maximum Vertical scan rate
--------------------------
This describes the rate in which the monitor can display screens.  Otherwise known 
as the refresh rate.  This is typically measured in units or Hertz (Hz).

This information is usually available within the documentation that was supplied 
with your monitor in a section detailing specifications or capabilities.  If this 
is not available, please contact your monitor supplier for more information regarding 
this area.


Installation
============

The refresh rate program can automatically sense the capabilities of a DDC (PlugnPlay) 
monitor.  If you monitor is not DDC compliant, you will need to supply some additional 
data to the refresh rate control program to allow correct operation.  The data required 
has already been been mentioned above (ie. Max resolution, Max refresh rate, and Max 
line rate).


*** Warning: using settings which exceed the limits of your monitor may damage your 
    monitor permanently.  Please see the specifications in your monitor documentation 
    or ask your monitor supplier for further details regarding the capabilities of the 
    monitor.


Syntax
======

CONTROL  [-i] [-u] [-vnnn] [-hnnn]

where	
i	Show mode information (Verbose mode)
u	Remove from memory
vnnn	Set maximum refresh rate
hnnn	Set maximum line rate

Note: 
The maximum refresh rate input can accept values in the range 60 - 250 Hz.
The maximum line rate input can accept values in the range 28 - 150kHz 
(or 28000 - 150000 Hz).



For example: to setup the refresh rate control program to use a monitor capable 
of 48kHz and a maximum refresh rate of 90Hz, use the following command line.

	CONTROL -i -v90 -h48
or
	CONTROL -i -v90 -h48000

The -i option can be omitted from the command line, but proves useful for mode 
information.


Uninstall
=========

To uninstall the refresh rate control program, use the [-u] option.  This unloads 
the program from memory.  The refresh rate control program can also be removed by 
rebooting your system.

For example: to uninstall the refresh rate control program from system memory, use 
the following command line.

	CONTROL -u


*** Please Note: Once the refresh rate control program is loaded with monitor settings, 
    to redefine the settings, the program needs to be uninstalled before the new settings 
    are used.



VideoLogic Support Team
September, 96
