Category : Alternate Operating Systems - Quarterdeck DesqView, CP/M, etc
Archive   : QWHITE13.ZIP
Filename : XGA.TEC

 
Output of file : XGA.TEC contained in archive : QWHITE13.ZIP

ID:XG XGA Video and Quarterdeck Products
Quarterdeck Technical Note #208 Filename: XGA.TEC
by Quarterdeck Testing & Compatibility CompuServe: XGA.ZIP
Last revised: 3/09/92 Category: HW

Subject: Using IBM's XGA video adapter with Quarterdeck products.


XGA.TEC

This is about XGA, a new high-resolution video standard developed by IBM,
and how it works with Quarterdeck products.


WHAT DO I DO ABOUT THE "UNRECOGNIZED MICROCHANNEL ADAPTER 8FDB" REPORT WHEN I
BOOT WITH QEMM-386 (OR QEMM 50/60 OR QRAM)?

Add this line:

8FDB XGA Video Adapter
/NT

to the file "MCA.ADL" in the QEMM (or QRAM) directory. All the "/NT" does is
pass the NT parameter to QEMM-386; the only service this provides is to keep
the QEMM-386 logo from being defaced during boot.

DOES THIS CARD USE HIGH ADDRESS SPACE?
The XGA card has an Adaptor ROM whose position cannot be set with the
Reference Diskette: it is self-configuring only. QEMM-386 detects this use
of the high address space and does not map over it. Version 6 of QEMM-386
does not Stealth this ROM because it is not accessed by interrupt.

WINDOWS ENHANCED MODE
Does Windows complain about a video conflict when QEMM-386 is loaded?
Does it report "Cannot load enhanced memory manager"? The problem is a bug in
XGAVDD.386, Windows' XGA driver. It will not load if there is RAM at the
first 4K region of the 32K region in which the XGA ROM is located. Therefore,
on a system with the XGA at D600-D7FF, it fails if QEMM-386 has placed High
RAM at D000-D0FF. So an eXclusion of D000-D0FF ("X=D000-D0FF") on the
QEMM386.SYS line of the config.sys:

device=c:\qemm\qemm386.sys ram x=d000-d0ff

fixes the problem. A better solution is to use the default Windows *VDDVGA
driver instead of XGAVDD.386. We know of no adverse consequences to doing
this; you may still use XGA video modes in Windows Enhanced with the *VDDVGA
driver. This is done by replacing the line:

display=XGAVDD.386

in the SYSTEM.INI file with:

display=*VDDVGA

WINDOWS STANDARD MODE
You can't run Windows Standard mode in an XGA video mode under versions
of QEMM-386 up to and including 6.00. It frequently seems to work, but
eventually the system crashes and reboots. Using Windows Standard mode in a
VGA mode is no problem. QEMM-386 6.01 and later versions are able to work
with Windows Standard Mode configured for XGA.

DESQVIEW
DESQview does not support XGA-specific modes. DESQview loses control of
the screen completely when a program enters an XGA-specific mode. DESQview
cannot display its menus or other DESQview windows on the screen, though the
XGA application can display successfully from within DESQview. A work-around
would be to switch a program running in an XGA mode to text mode (for example,
shell to DOS or open a DOS window from Windows 3) when you wish to switch to
another DESQview window. There are no problems using an XGA card in VGA modes
in DESQview.


************************************************************************
*This technical note may be copied and distributed freely as long as it*
*is distributed in its entirety and it is not distributed for profit. *
* Copyright (C) 1991-2 by Quarterdeck Office Systems *
************************ E N D O F F I L E *************************