
  SVGA Trouble Shooting
 =======================

 According to Jordan Hargrave,  the Author of the  Super VGA Graphics Inter-
 face used by "Astrometrica",  this Interface is compatible to the following
 graphics cards:
  
  VESA, Weitek, Chips & Technologies, Paradise, Compaq, Video7, Genoa,
  Everex, Cirrus 54XX, Cirrus 64XX, Trident 8800/8900, ATI, Ahead A & B,
  NCR, S3, Avance Logic 2101, MXIC 68000, Acumos, Realtek, Primus 2000,
  Oak, UMC, HMC and Tseng ET3000/ET4000/ET3000W32

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 PROBLEM:  The mouse cursor writes garbage to the screen, or does not appear
           at all.

 CAUSE:    Your mouse driver is not compatible with  high  resolution  Super
           VGA modes.

 SOLUTION: Use a mouse driver software that is compatible with high res SVGA
           modes. For example,  the Logitech mouse driver works fine on VESA
           compatible cards,  but  make sure that the VESA overlay module is
           loaded. To do so, the file LMOUSE.INI must include these lines:

           Module=[VESA.OVL]

           Ask your computer dealer on updating your mouse  driver  software
           for a version with SVGA support!

           Another solution may be the use of the  TSR  tool HGXMOUSE, which
           you can find on the  "Astrometrica"  diskette  in  the  /HGXMOUSE
           directory.  This  program,  which must be loaded before you start
           "Astrometrica",  is  an  extension  to  the mouse driver software
           which provides SVGA compatible mouse routines.

           Note that HGXMOUSE is shareware,  and if you make use of it,  you
           are asked to pay a shareware fee.  Please  read the  HGXMOUSE.TXT
           file for details.

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 PROBLEM:  The blink comperator does not display a third or fourth image.

 CASUE:    Your graphics card has not enough memory to provide more than two
           graphics pages, or it won't provide more than two images.

 SOLUTION: To support four graphics pages,  the graphics card needs at least
           512 kB video memory at 640x350, and at least 1 MB video memory at
           800x600.

           If video memory is not the problem, the graphics card  won't  let
           you access more than two graphics pages. Some cards, for example,
           will not support more  than two graphics pages (the VGA standard)
           at the standard VGA mode 640x350. In that case, blinking three or
           four images may work at 800x600. Still other graphics cards (some
           of the new generation cards optimized for  grapical  user  inter-
           faces, for example) simply do not support switching to a third or
           fourth page, a feature rarely used by any software. There is, un-
           fortunately,  no  solution other than trying a different graphics
           card.

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 PROBLEM:  The graphics don't work properly,  the images and/or text appears
           disorted or scambled.

 CAUSE:    The Super VGA driver does used by  "Astrometrica"  is  apparently 
           not compatible with your graphics card.

 SOLUTION: Check the documentation of you graphics card:  Possibly, there is
           a TSR program or device driver  provided  that  emulates  a  VESA 
           compatible graphics card. Sometimes, there is a shareware or even
           a freeware available to provide VESA support.

           If you can't get it to work, you may start the software using the
           command line parameter  /NoSVGA.  In  that  case,  "Astrometrica"
           loads a standard VGA driver instead of the  Super VGA  driver. Of
           course, you can neither use the high resolution 800x600 mode, nor
           blink more than two images, then.
           
           If the image can not be displayed at  full  resolution  sing  the 
           standard VGA mode (or, with very large Images,  even at Super VGA 
           resolution),  2x2,  3x3 or 4x4 pixels will be binned for display.  
           All calculations, however, will be done using the full image data 
           available.  Also,  note that a magnified portion of the image can 
           be displayed at full resolution using the zoom (F8-key) mode.

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