U7 TDK ZJY-2P U8 TDK ZJY-2P U9 TDK ZJY-2P 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.