










SVGA

An Image Viewing Utility

Version 1.1 - April 1992





Program Reference Manual





Copyright (C) 1992 by John P. Silva
All Rights Reserved






John P. Silva
3429 Maywood Dr.
Richmond, CA  94803

(510) 222-9255

Internet: jsilva@cogsci.berkeley.edu
GE Mail:       J.SILVA1

SVGA Version 1.1 - April 1992	    -i-			 TABLE OF CONTENTS
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SVGA LICENSE INFORMATION                                           1
     Shareware & Registration                                      1
     Terms and Conditions                                          1
     Limited Warranty                                              2
     Limitation of Liability                                       2
     Shareware Distributor License Agreement                       2
     Trademark Information                                         2
INTRODUCTION TO SVGA                                               3
     Program Description                                           3
     Features                                                      3
     Machine Requirements                                          3
USING SVGA                                                         4
     SVGA Command Line                                             4
     Installation                                                  4
     Environment Variables                                         4
          SVGA Environment Variable                                4
          TEMP Environment Variable                                4
     File Selection Screen                                         5
          Getting Help                                             5
          Moving Around                                            5
          View Image                                               5
          Change Directory                                         5
          Change drive                                             5
          Toggle 4DOS Description Display                          5
          Toggle Image Resolution Display                          5
          Toggle 43/50 Line Mode                                   5
          Toggle Automatic Resolution Selection                    5
          Change Display Resolution                                5
          Get File Information                                     6
          Edit 4DOS Description                                    6
          Rename File                                              6
          Delete File                                              6
     Image Display Screen                                          6
          Getting Help                                             6
          Moving Around                                            6
          Color Mix                                                6
          Brightness                                               6
          Restore Palette                                          6
          Change Display Resolution                                6
	  Palettes and TrueColor Video Modes                       6
APPENDIX                                                           7
     Troubleshooting                                               7
          386 Memory Managers                                      7
          Tseng Labs ET4000 HiColor and Video Snow                 7

SVGA Version 1.1 - April 1992	    -1-		  SVGA LICENSE INFORMATION
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SVGA LICENSE INFORMATION
     
  Shareware & Registration
     SVGA is Copyright (C) 1992 by John P. Silva.  All Rights Reserved.
     
     SVGA is SHAREWARE, user supported software for the IBM PC.  SVGA is
     made available for a free 30 day trial period.  If you find this
     program useful, you may license your copy of the program for use on
     one machine by sending US$15 to:
     
             John P. Silva
             3429 Maywood Dr.
             Richmond, CA  94803  U.S.A.
     
  Terms and Conditions
     SVGA is copyrighted software, and all rights are reserved.  SVGA may
     not be changed or modified in any way except by the author.  SVGA is
     SHAREWARE, and may be freely distributed, as long as it remains in its
     complete form with all support and documentation files.  It may be
     used for a 30 day free trial period.  Regardless of how the copy is
     obtained, it is requested that all users comply with the following
     licensing and registration provisions if they continue to use it after
     the 30 day trial period:
     
     You may license multiple copies of SVGA with discounts as follows:
          1 - 10 copies       US$15
          11 - 50 copies      20% discount
          51 - 100 copies     35% discount
          100+ copies         50% discount
          Site License        US$750
     
     Manuals and diskettes for the latest version of SVGA are available to
     registered users for US$10 per copy.

     All prices and discounts are subject to change without notice.
     Discounts apply only to individual orders, they are not cumulative.
     
     Registration entitles you to:
          Use all updates at no cost.
          Receive free updates by sending me a diskette and a self
          addressed stamped disk mailer.
          Receive free technical support either by phone (you call me) or
          by electronic mail.
     
     SVGA should be distributed intact, with all executable and
     documentation files.
     
     Registered users may install SVGA on more than one machine, provided
     they are the only user on each machine.  The registration and license
     policy is similar to a book, which can be taken with you but used only
     by you.

SVGA Version 1.1 - April 1992	    -2-		  SVGA LICENSE INFORMATION
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  Limited Warranty
     The author makes no warranty of any kind, either expressed or implied.
     This includes, but is not limited to, implied warranties of
     merchantability, and fitness for any particular purpose with respect
     to both the software and the documentation included in this package.
     
     IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     CONSEQUENTIAL, OR INCIDENTAL DAMAGES ARISING OUT OF THE USE OR
     INABILITY TO USE THIS PRODUCT EVEN IF THE AUTHOR HAS BEEN ADVISED OF
     THE POSSIBILITY OF SUCH DAMAGES OR CLAIM.  Some states do not allow
     the exclusion or limitation of liability for consequential or
     incidental damages, so the above limitation may not apply to you.
     
     The warranties set forth above are in lieu of all other express and
     implied warranties, whether oral, written, or implied, and the
     remedies set forth above are your sole and exclusive remedies.
     
  Limitation of Liability
     In no case shall the authors liability exceed the license fees paid
     for the right to use SVGA or five dollars (US$5.00), whichever is
     greater.
     
  Shareware Distributor License Agreement
     Shareware distributors may distribute this program as long as the
     Author has been notified prior to ANY distribution.  The "per disk"
     charge may not exceed $10 and the shareware distributor will not
     change the above license agreement for the end user of SVGA.  End
     users are still required to register each shareware copy of SVGA.
     
  Trademark Information
     Graphics Interchange Format (C) Copyright CompuServe Incorporated.
     GIF(sm) is a Service Mark owned by CompuServe Incorporated.  For
     further information, please contact:
          CompuServe Incorporated
          Graphics Technology Department
          5000 Arlington Center Boulevard
          Columbus, Ohio  43220    U.S.A.
     
     Truevision is a registered trademark of Truevision, Inc.
     TARGA is a registered trademark of Truevision, Inc.
     
     4DOS(tm) is a trademark of JP Software, Inc.
     
     QEMM-386(tm) is a trademark of Quarterdeck Office Systems.
     
     Other product and company names are trademarks of their respective
     owners.

SVGA Version 1.1 - April 1992	    -3-		      INTRODUCTION TO SVGA
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INTRODUCTION TO SVGA
     
  Program Description
     SVGA is an easy to use multi-format image viewer designed to quickly
     browse through a collection of image files.
     
  Features
     SVGA is a general purpose image file viewer for VGA and SuperVGA with
     the following features:
     
      High speed viewing of the following image formats:
      1.CompuServe GIF87a and limited GIF89a support.  SVGA only supports
        the image storage portion of GIF89a, not the pseudo-animation and
        text extensions.
      2.ZSoft PCX files (including 24 bit PCX).
      3.MicroSoft Windows BMP files (including 24 bit BMP), both
        compressed and uncompressed.
      4.Truevision TARGA files, types 1, 2, 9, and 10.     

      Self configuring for most display boards using Ahead, ATI, C&T,
      Everex, Genoa, NCR, Headland, Oak, Paradise, S3, Trident, Tseng Labs
      (ET3000/ET4000), Video 7, and Western Digital chips  (See the
      Appendix for supported chipsets).  SVGA fully supports the VESA
      standard, and will use the VESA standard (through BIOS or TSR
      support) if desired.
     
      Supports viewing TrueColor images on VGA, HiColor, and Everex
      TrueColor display adapters.
     
      SVGA can view images much larger than the available video hardware
      may allow.  This is accomplished by preloading the image and then
      displaying it in whichever mode the user desires.  This allows the
      display mode to be changed on the fly without having to reload the
      image from disk.
     
      Automatic detection of 80386/80486 processors for faster image
      display.
     
      Will use all available main memory, EMS, XMS, and hard disk space to
      view images up to 8192 x 8192 in size.  If there is insufficient
      physical memory to load an image, SVGA will create temporary files
      on disk as a virtual memory buffer to load as much of the image as
      is possible.
     
      Fully supports 4DOS compatible file descriptions, and can edit file
      descriptions at the file display screen.
     
      Updates the display screen automatically when images are renamed,
      deleted or descriptions changed.
     
      Can be compressed with PKLite or other executable file compressors
      with no ill effects.
     
  Machine Requirements
     SVGA requires a VGA or SuperVGA equipped IBM PC compatible computer
     with a minimum of 512k of memory.  2 MB of memory or more is desired
     for efficient viewing of most image files.

SVGA Version 1.1 - April 1992	    -4-				USING SVGA
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USING SVGA
     
  SVGA Command Line

     SVGA Command Line Format:
     
               SVGA [/badrv4] [/x xres] [/y yres] [/p startpath]
     
     The /b option selects BIOS for screen I/O rather than direct screen
     writes.
     The /a option selects automatic resolution selection at startup.
     The /d option selects display of 4DOS descriptions at startup.
     The /r option selects file list image resolution display at startup.
     The /v option selects the VESA interface if VESA is installed.
     The /4 option selects 43/50 line mode at startup.
     The /x and /y options specify the largest allowable display mode at
     startup.
     The /p option specifies the path SVGA should switch to at startup.
     
     All command line switches are optional, and may be specified in any
     order.
     
  Installation
     Installation of SVGA is straightforward.  Simply place the SVGA.EXE
     executable someplace in the DOS path, and the rest is automatic.  SVGA
     will automatically detect your machine, memory and video adapter.
     (See Appendix for supported chipsets.)  SVGA requires no configuration
     or data files for correct operation.   However, there are a number of
     DOS environment variables which may be set to enhance program
     operation.
     
  Environment Variables
     
     SVGA Environment Variable
       Default command line switches may be specified in the dos
       environment variable 'SVGA'.  DOS environment variables are set by
       giving a command to DOS before running SVGA.  You can add these
       commands to your AUTOEXEC.BAT file.
       
       The format of the SVGA environment variable is identical to the
       SVGA command line format.  All command line options may be set in
       this variable.
       
       Example:  set SVGA=/dr4 /x 800 /y 600 /p C:\GIF
       
       These options select as default 4DOS descriptions, image resolution
       display, 43/50 line mode, 800x600 startup resolution (or the
       largest resolution available below 800x600), and a startup path of
       C:\GIF.
       
     TEMP Environment Variable
       The DOS environment variable 'TEMP' may be used to direct SVGA to
       place its virtual memory buffers in a specific location.  If the
       'TEMP' variable is not set, SVGA will place the virtual memory
       buffers in the current working directory.  This may not be
       desirable behavior.  It is recommended that 'TEMP' be set to a
       directory on a hard disk with more than 2 MB of free space.

SVGA Version 1.1 - April 1992	    -5-				USING SVGA
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  File Selection Screen
     The File Selection Screen consists of the display mode list, the file
     selection area, and the help line.  The currently selected mode is
     displayed in yellow.
     
     Getting Help
       The F1 key will display the SVGA help and program information
       screen.
       
     Moving Around
       You may position the cursor on the screen by using the arrow keys,
       the HOME/END keys, the PGUP/PGDN keys, or by pressing the first
       letter of the desired filename.  HOME will move the cursor to the
       start of the list.  END will move the cursor to the end of the
       list.  PGUP will jump up one screenful of names.  PGDN will jump
       down one screenful.
       
     View Image
       To view an image, position the cursor to the desired image and
       press the Enter key to initiate image display.
       
     Change Directory
       To change the current directory, position the cursor to the desired
       directory and press the Enter key to select the directory.  When
       changing to the directory one level up, the cursor will be
       positioned at the name of the previously selected directory.
       
     Change drive
       The F2 key will bring up the drive selection dialog box.  Simply
       press the desired drive letter, and SVGA will attempt to change to
       the desired drive.  If an error occurs, SVGA will remain at the
       current drive.
       
     Toggle 4DOS Description Display
       The F5 key will toggle the display between multiple columns and
       4DOS descriptions.  The default mode is multiple column display.
       
     Toggle Image Resolution Display
       The F6 key will toggle the display between file date/time and image
       resolutions.  The default mode is file date/time display.
       
     Toggle 43/50 Line Mode
       The F7 key will toggle between the startup mode and 43/50 line
       mode.  The default mode is usually 80x25 text mode.  Certain
       utilities such as UltraVision may change the default mode.  SVGA
       fully supports the large screen sizes provided by such utilities.
       
     Toggle Automatic Resolution Selection
       The F8 key will toggle between locked mode and automatic selection
       mode.  The mode line will change to indicate current mode.
       Automatic mode is indicated when all shown resolutions are the
       same color.  The default mode is locked.
       
     Change Display Resolution
       The F9/F10 keys will decrease and increase the current mode,
       respectively.  The default mode is the mode with the highest
       possible resolution.

SVGA Version 1.1 - April 1992	    -6-				USING SVGA
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     Get File Information
       Information on the current file can be obtained by pressing Alt-I.
       This information is the same information that is found under
       various aspects of the file display screen.

     Edit 4DOS Description
       4DOS descriptions can be edited by pressing Alt-E.  Descriptions
       may be edited whether or not descriptions are currently being
       displayed.
       
     Rename File
       The current file can be renamed by pressing Alt-R.
       
     Delete File
       The current file can be deleted by pressing Alt-D.  This also
       deletes the description in the 4DOS description file.
       
  Image Display Screen
     
     Getting Help
       The '?' key will show available commands in Image Display Mode.
       
     Moving Around
       The arrow keys will scroll the image around the screen, if the
       current image is larger than the current display mode.  Press
       ESCAPE or Enter to return to the File Selection Screen.
       
     Color Mix
       F1 will decrease the red content of the image.
       F2 will increase the red content of the image.
       F3 will decrease the green content of the image.
       F4 will increase the green content of the image.
       F5 will decrease the blue content of the image.
       F6 will increase the blue content of the image.
       
     Brightness
       F7 will darken the image.
       F8 will lighten the image.
       
     Restore Palette
       Alt-F10 will return the palette to normal.
       
     Change Display Resolution
       F9 will decrease the current display mode.
       F10 will increase the current display mode.

     Palettes and TrueColor Video Modes
       The palette editing functions in SVGA only effect the paletted
       video modes, such as the standard 256 color SuperVGA video modes.
       TrueColor video modes have no palette, and cannot be color
       corrected using the F1-F8 keys in view mode.

SVGA Version 1.1 - April 1992	    -7-				  APPENDIX
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APPENDIX
     
  Troubleshooting
     
     386 Memory Managers
       SVGA may have difficulty detecting ATI, Genoa, Paradise and Western
       Digital video adapters when running QEMM-386 or similar memory
       management products which hide the system ROMs behind useable
       memory (QEMM calls this "stealth mode").   To correct this
       difficulty, you should either exclude the range C000-C1FF from use
       by the memory manager, or arrange to have the page frame mapped
       into the range C000-CFFF (this works with QEMM, but may not work
       with other memory managers).  This allows SVGA to correctly access
       the necessary information in ROM.
       
     Tseng Labs ET4000 HiColor and Video Snow
       Most Tseng ET4000 based video boards have timing problems which
       manifest themselves as random changes to pixel data written to
       video memory.  These changes typically appear as brightly colored
       pixels or "snow" in the image being viewed.  This problem is
       particularly apparent in HiColor video modes.  It is a hardware
       bug, not a problem in SVGA.

