@8FDB.ADF - IBM XGA Display Adapter/A 
C8FDB.ADF - Init file for _8FDB.ADF

U10 37F0842
U11 1888676 (Toshiba TC110GC9A6)
U20 OKI M51257AL-12
U27 37F9567
U34-U41 Video RAM 
U44 40.0000 MHz
U45 44.9000 MHz
U46 28.3220 MHz
U47 41.5390 MHz
U48 25.1750 MHz

U34-U41 Toshiba TC524256BZ-10 or NEC D42274V-10 

  This card shares the same video chipset as the 9590 planar.

Oscillator Functions
  Finally beat them out of Peter2 Jun 00
U44 40.0000 MHz  DMA Clock / 2
U45 44.9000 MHz  Pixelclock 1024 x 768, 43.5Hz Interlaced (8514/A) mode
U46 28.3220 MHz  VGA / Text mode
U47 41.5390 MHz  Pixelclock 132-colums mode
U48 25.1750 MHz  Pixelclock 640 x 480 / 400 modes

Xfree86 Beginning
Chipset "XGA-1"
Instance 6 
IObase 0x2160 
COPbase 0xdff00
MEMbase 0xfd800000
BIOSabse 0xde000
DACspeed 45 
Videoram 1024   (Easy, it's either 512 or 1024)
Clocks 28.322 25.175 41.539 44.9

XGA Generalities
   The XGA card is an entire graphics subsystem that does not have to rely on a video subsystem on the motherboard of the machine where it is installed. The XGA card is a Bus Master, which means it can do its own processing and memory accesses without having to use the main system processor, providing faster video processing and freeing up the main processor for other tasks.
   The drivers and the card itself have been optimized to work with the 386 32-bit instruction set. The XGA card comes standard with 512KB of VRAM which provides a maximum resolution of 1024 x 768 with 16 colors. If the memory is upgraded to a full 1MB the maximum increases to 1024 x 768 with 256 colors.

Possible Erratum
  The XGA Adapter was upgradeable to 640 x 480 with  65,536 colors (!) and 1024 x 768 with 256 colors by means of the PS/2 Video Memory Expansion Option.


9595 Main Page

  On IBM PS/2 computers with a 16-bit bus, and XGA, the following error message may appear after  installing the XGA drivers in Microsoft Windows NT: 
       The aperture enabled for the xga device is invalid, please enable the 4MB aperture
       (preferred) or 1MB aperture using the xga reference disk. 
  This error occurs on 16 MB 16-bit bus PS/2 computers that support a maximum of 16 MB of RAM, such  as the model 9556 or 9557. 

  The PS/2 XGA subsystem provides three possible apertures, or windows, to video memory in the
  physical memory address space of the system. Aperture size options are 64KB, 1MB, and 4MB. The 4MB aperture option is not available on 16-bit computers, such as those based on the 80386 SX processor. The 4MB Aperture is also not available if the XGA subsystem is plugged into a 16 bit slot in a 32 bit computer and is only accessible by 32 bit protect mode drivers, such as the drivers used by Microsoft Windows NT. 
  Currently, Microsoft Windows NT only supports XGA with an Aperture of 1MB, or 4MB enabled. On 16-bit IBM PS/2 computers with 16MB RAM, the 1MB meg aperture cannot be enabled. 

  According to IBM , a possible workaround is to use the standard VGA which does not require this option to work, or decrease the amount of physical RAM below 16MB. 


9595 Main Page