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          Classic Above Board Video Board Compatibility: A-D              
                                                                          
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 AHEAD VIDEO ADAPTER

     Customers report Conditional Compatibilty between current Above Boards
     and the Ahead Video Adapter. Since this board apparently fluctuates
     reserved memory accesses between 8- and 16-bit when set for 16-bit
     accesses, it is necessary to set this for 8-bit only accesses.  Jumper
     W1 sets for 8- or 16-bit accesses and needs to be removed to set for
     only 8-bit operations.

     The Ahead Video Adapter is a 16-bit VGA Wizard 3270, it works with IRMA
     boards to give 132 column displays.

 AST

 AST 3G

     *FIELD REPORTS* of compatibility with Above Boards.

     Tech Notes: From one field report, when the AST board emulation switch
     is ON, AB extended memory doesn't work.  With it OFF, everything works
     great.

 AST VGA (8-BIT)

     Tested here and found to be Compatible with AB Plus.

     Technical Notes:
         AST VGA is a short video board supporting VGA. This is an 8-bit
         board that occupies addresses C0000H to C5FFFH.

         Tested here with with no problems other than using EXPF = C800 with
         AB providing expanded memory to avoid memory conflicts in the lower
         C0000 area. Extended memory worked fine.

 AST VGA PLUS (16-BIT)

     *Field Report* of compatibility with Above Boards.

     Tech Notes: We've heard different reports on this board.  It looks like
     there are two different versions of the board.

        Symptom: EMM reports "All memory is being used as conventional or
         extended memory. There is no expanded memory to manage."

         Solution:  AB works with this board in a 6/8MHz system with
         SETBOARD set for 8MHz.  If the bus speed is anything faster, no
         matter what Setboard has, the Above Board memory will fail.

        Symptom:  EMM hangs on boot.

         Solution: Set the VGA board to 8-bit mode by turning switch 2 off.

 ATI

 ATI WONDER

     *FIELD REPORTS* of compatibility with Above Boards.

     Tech Notes:ATI boards with BIOS version 4.03 or earlier will not work
     with the Clock on the discontinued AB PS/PC. ATI is reported to have an
     upgrade program.  Have user disable clock until they get new BIOS from
     ATI.

 ATI VGA WONDER

     *FIELD REPORTS* of compatibility with Above Boards.

     Tech Notes: When using ATI BIOS rev 1.03 or later, the system may hang
     unless the ATIVIDEO.SYS driver is loaded -before- EMM.SYS.

         I/O ports: 3B0 to 3DF
         Memory Addresses: A000 - C7FF
         ATI Bus Mouse uses I/O port 23C, INT 5

 ATI VGA WONDER XL SERIES

     *FIELD REPORTS* of compatibility with Above Boards.

     This board can be set for 8-bit or 16-bit operation using the VGA
     Utilities software that comes with the board.  This board needs to be
     set for 8-bit operation if the Above Board is supplying any expanded
     memory.

 AT&T TARGA

     Compatible with ABs.

     Tech Notes:
     The TARGA board allows memory settings at 8000h, 9000h, A000h, D000h,
     or E000h.  The switch settings for these are on P. 3-3 to 3-5 of the
     Hardware Configuration section of the TARGA manual.  (This information
     comes from a single TARGA manual and may not be 100% applicable to
     different revs. of the board/manual.)

 AT&T VDC 600 VGA

     *FIELD REPORTS* of limited compatibility with Above Boards. The AT&T
     VDC 600 (video display board) is a 16bit VGA, however it will run into
     a 16bit conflict with an Above Board providing expanded memory,
     (extended memory works fine).

     Apparently the AT&T VDC 600 does a true 16bit access through the data
     bus but fluctuates between 8 and 16bit accesses when using reserved
     memory. If it were doing a true 16bit access through reserved memory
     there would be no problems with expanded memory. Since it isn't it will
     be necessary to change the AT&T VDC 600 to 8-bit operation (move switch
     4 to the down or off position) to use it in conjunction with expanded
     memory.

 AUTOMASTER EGA

     *FIELD REPORT* of LIMITED compatibility with Above Boards, this EGA
     board is apparently INCOMPATIBLE with expanded memory. Above Boards
     providing conventional or extended memory work fine with this EGA.

 COMPAQ VGA (EMM PARAMETER 16BIT=03)

     Compatible with Above Boards.

     If using EMM with the Compaq VGA use the EMM parameter:16bit=03. Must
     have EMM Classic Bus EMM version 4.0 rev C, (disk labeled date 5/89) or
     newer.

     In general the "16BIT=" parameter controls how the AB sets up memory
     accesses in the C000 to E000 address range.  03 causes the segments in
     the C000-C7FFh range to be set up for 16-bit accesses, which is where
     the Compaq VGA is residing in this case. For more information on the
     "16BIT=" parameter see the "16bit=" Scoop Cell.

     In a very few cases we've seen where the Compaq VGA isn't in its native
     16bit mode, it has been jumpered to 8bit mode. If this happens EMM will
     lock up with the 16BIT=03 parameter.

 COMPUAD HERC MONO BOARD

     *FIELD REPORTS* of compatibility with Above Boards.

     Tech Notes:
     One Customer reported the following symptom. After installing EMM in an
     IBM AT with this video board, a warm boot would fail.  Cold boot would
     work fine but on a warm boot the computer would give 1-long and 2-short
     beeps then require a cold boot to restart.

     Adding EXPF=C800 to the EMM command line in CONFIG.SYS solved the
     problem. With EMM at the C400 address, the problem would still occur.

 DATA ACQUISITION CONTROL

     *FIELD REPORTS* of incompatibility with Expanded memory, works fine
     with an Above Board providing extended or conventional memory.

     This Hi-Res PGA board use reserved memory at C600 and uses only 1k,
     HOWEVER, the systems with this video card will most likely also have a
     Proprietary Network Board at D000-DFFF.  Neither are switchable.

     Tech Support ph: (617) 439-0160

 DELL VGA

     FIELD REPORT of compatibility.

     Tech Notes:
     FIELD REPORT that the Dell VGA board has switches to access various
     addresses in reserved memory. These switches can be set to reside in
     various places in the D000 range. Make sure the customer has the Dell
     VGA switches set to operate at some address other than where EMM is
     trying to go.

     Check for 16-bit board, change to 8-bit.

 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.



End of file                 Intel FaxBack # 1434          August 7,1992
