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          Classic Above Board Video Board Compatibility: T-Z              
                                                                          
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 PROBLEMS W/ZENITH EGA BOARDS AND EMM

     If the customer is experiencing video problems when EMM.SYS loads, they
     will probably need new Above Board software. They will need SOFTSET and
     EMM versions with an Installation Diskette label date of 5/89 or later.

     Some background: Zenith ships at least two different EGA boards with
     their ZW-248 systems. One is made by SIGMA, the other by Paradise.
     Both use the same ROM driver on the board, which makes use of a 4K
     "SCRATCH PAD" area to store some information for the EGA board's
     operation.  Intel's old EMM and INSTALL programs were unable to detect
     this "scratch pad" and caused the information to be corrupted. This
     caused erratic operation of the EGA.

 ZENITH EGA MODEL 449 & AB286
     Customers report compatibility with Above Boards and this video card.

     Tech Note: We have one customer report that the discontined INSTALL
     software will work if this board's auto emulation is turned off,
     otherwise it would be necessary to manually install the Expanded Memory
     Manager. We have no reports of any problems with the SOFTSET program
     (which replaced the INSTALL program).

     (This board made by Sigma Designs)

 TATUNG MODEL VGA-16

     *FIELD REPORTS* of compatibility with Above Boards, although there are
     some issues to be aware of when setting up expanded memory with this
     VGA adapter. Extended memory works great with this adapter without any
     modifications.

     Since this 16bit VGA card doesn't do a true 16bit reserved memory
     access (it fluctuates between 8bit and 16bit reserved memory accesses),
     the VGA card needs to be set to an 8bit mode in order to work with our
     Expanded Memory Manager. If it did a true 16bit access we could add the
     16BIT=03 parameter to the EMM.SYS device driver line to get this
     working, but this parameter will lock up the system the first time this
     VGA card does an 8bit access of reserved memory.

     16-bit VGA board similar to the Video 7 VGA.   There is a switch for
     setting the ROM to 8-bit or 16-bit.   Set it to 8-bit for it to work
     with AB expanded memory. Uses A0000-CA7FF.

 TAXAN PX1280

     *Field Reports* of compatibility with Above Boards.

     This EGA video board uses address ranges: A0000 - C4FFF which could be
     an issue if the Above Board is providing expanded memory.

     Customer Note:If this board is used in conjuction with the Taxan
     Scanner in an 80286-based computer there won't be sufficient memory for
     EMM to load.  Taxan scanner board uses D0000-DFFFF.

 TRIDENT VGA

     *Field Reports* of compatibility with Above Boards. There are two
     potential conflicts when the Above Board is set up to provide expanded
     (LIM EMS) memory:

        This VGA card uses a 32k area that the Above Board can use, from
         C0000 - C7FFFh.
        This 16bit VGA doesn't do true 16bit accesses through reserved
         memory, it fluctuates between 8bit accesses and 16bit accesses.
         Because it doesn't do true 16bit accesses it can cause lockups with
         current Above Boards providing true 16bit accesses for expanded
         memory. The only solution is to be put the VGA into 8bit operation
         by removing jumper J1.

 VERTICOM PGA

     *Customer Reports* of compatibility with Above Boards. There are two
     potential conflicts when the Above Board is set up to provide expanded
     (LIM EMS) memory:

        This VGA card uses a 64k area of the 128k area that the Above Board
         can use, from C0000 - CFFFFh.
        This 16bit VGA doesn't do true 16bit accesses through reserved
         memory, it fluctuates between 8bit accesses and 16bit accesses.
         Because it doesn't do true 16bit accesses it can cause lockups with
         current Above Boards providing true 16bit accesses for expanded
         memory. The only solution is to be put the VGA into 8bit operation.

 VIDEO 7

 VIDEO 7 VGA FASTWRITE / VRAM

     *FIELD REPORTS* of compatibility with current Above Boards. There are
     two potential conflicts when the Above Board is setup to provide
     expanded (LIM EMS) memory:

        This VGA card uses a 32k area that the Above Board can use, from
         C0000 - C7FFFh.
        This 16bit VGA doesn't do true 16bit accesses through reserved
         memory, it fluctuates between 8bit accesses and 16bit accesses.
         Because it doesn't do true 16bit accesses it can cause lockups with
         current Above Boards providing true 16bit accesses for expanded
         memory. The only solution is to be put the VGA into 8bit operation
         by setting Switch 6 on the VGA board to the off possition.  This
         disables the 16-bit ROM accesses and enables the 8-bit accesses.
         The Video RAM accessing is still 16-bits.  Performance degradation
         of the VGA board is minimal.

     The VRAM board is similar and switch 6 instructions are the same.

 VEGA VGA

     *Field Reports* of compatibility with Above Boards.There are two
     potential conflicts when the Above Board is setup to provide expanded
     (LIM EMS) memory:

        This VGA card uses a 32k area that the Above Board can use, from
         C0000 - C7FFFh.
        A customer reported having problems with Paradox and Word Perfect
         5.0 after installing an AB and EMM.  Video 7 informed the customer
         that the VEGA version 1.04 of software was incompatible with LIM
         4.0.  They have a free upgrade to a new BIOS (and some other fix
         not described).

 VISION TECHNOLOGIES EV620 VGA GRAPHICS ADAPTER

     This is a 16-bit VGA board. We have customer reports of compatibility
     with Expanded Memory (using EMM.SYS) and the EV620 when the EV620 is
     set for 8-bit operations. There are no issues with this video adapter
     when the Above Board or Matched Memory Classic is configured for only
     extended memory.

     To configure the EV620 for 8-bit operations you must set the following
     switches accordingly:

         SW3 OFF
         SW7 OFF
         SW8 ON

 VGA MEMORY USAGE

     Some general info:

     VGA's in general use ALL of A0000 to BFFFF for video data. These guys
     tend to be in EGA mode most of the time because software has to be
     rewritten to use REAL VGA capabilities. There are more and more REAL
     VGA applications being written daily.

     VGA mode itself has several modes i.e. 640 x 480 w/sixteen colors, 320
     x 200 w/256 colors (WOW the shading) and some others.

     The VGA board has TWO eproms located at C0000 to C7FFF which in effect
     is an extention of EGA (EGA used C0000 to C3FFF) so we can forget about
     the lower half of the C0000 area for use when providing expanded (LIM
     EMS) memory.

     Most VGA boards occupies (not necessarily always uses) the area from
     A0000 to C7FFF (160k!).

     IBM 's VGA in the PS/2 machines don't occupy the C0000 to C7FFF area
     because the BIOS supports it directly.

 WYSE 7190 VIDEO CARD

     * FIELD REPORT *
     This board use 16K of switchable memory addresses.  The possible
     combinations are as follows:

                       Switches   4    5     Mem. Address
                                 ---- ----   ------------
                                  On   On    CC00 - CFFF
                                  On   Off   D400 - D7FF
                                  Off  On    DC00 - DFFF

 ZENITH

 ZENITH Z449 & INSTALL AND TESTAB

     *Field reports* of compatibility with Above Boards.

     Tech Notes:
     TESTAB and the discontined INSTALL programs aren't compatible with this
     graphics board.

     If a customer is trying to install the Expanded Memory Manager
     (EMM.SYS) using the old INSTALL program, it won't work. They will have
     to install EMM.SYS into the CONFIG.SYS file manually, or use our newer
     software (SOFTSET).



End of file                 Intel FaxBack # 1444          August 26,1992
