190-182 IBM PS/2 XGA Display Adapter/A
37F9576 XGA BIOS Ver 2.00 20-07-90
37F9576 XGA BIOS Ver ?.?? 15/03/91
Note: Please check your XGA BIOS for
dates PAST 1990.
Products Developed at Hursley "Expressway" - XGA Adapter
Spacemont (a portmanteau of Space Mountain at
Disney World being the highest point in Florida) was a project
between Hursley and Boca to develop a follow-on to the VGA
PC graphics adapter. However, it fell foul of
compatibility and cost issues and was canned after 6
months in favor of an extension of the VGA (called rather
unexcitingly the XGA).
XGA Adapter /A 75X5887
TC524256BZ-10 or NEC D42274V-10 [NOTE: -80 VRAM works
Different XGA Display
J5 Function Solder pads for header to supply a base video. This function is performed by the Base Video Extension (BVE) right below the outline.
XGA Block Diagram
Flow of control and addressing signals, and the data flows from the external interfaces (PS/2 interface and Base Video Extension) through the components to the display.
POST in Adapter PROM
Fits in Base Video Extension (BVE) slot, providing Base Video to AVE [ex. Model 95]
XGA on planar
POST in the system ROM
Provides Base Video to Auxiliary Video Extension (AVE) (ex. Model 90)
XGA CPU Requirements
The XGA Adapter/ A can be used in all Micro Channel machines with a 80386, 80386SX or i486 processor. 80286 (and earlier) processors lack 32 bit registers and segment registers.
XGA Slot Width
The XGA Adapter/ A performs faster in a 32-bit slot, but it will still run in a 16-bit slot. However, for 32-bit operations, it will require two bus cycles instead of one, and memory addressability will be limited to 16MB.
XGA VRAM Size
Both planar and Adapter/A perform faster with 1 MB because the data path into the video display buffer memory is 32-bits wide. At 512 KB, the data path width is only 16-bits wide.
W98SE Supports 64K Colors
Yes, folks, I have been to the mountaintop, and it is good. W98SE has built-in support for 640x480 at 16/256/64K colors (finally!) and 1,024x768 at 16/256 colors.
Instance 6 (Address from Video Instance)
IObase 0x2160 (Address from Video Instance)
DACspeed 45 (fixed)
Videoram 1024 (Easy, it's either 512 or 1024)
Clocks 28.322 25.175 41.539 44.9
The XGA card is a Base Video card - it does not need a planar video subsystem. It is a Bus Master, able to do its own processing and memory accesses without using the system processor, providing faster video processing and freeing up the main CPU for other tasks.
The drivers and the card have been optimized to work with the 386 32-bit instruction set. The max resolution with 512KB of VRAM is 1024 x 768 with 16 colors, with 1MB the max is 1024 x 768 with 256 colors. When upgraded with the 512K [ PS/2 Video Memory Expansion Option], the XGA adds 640 x 480 with 65,536 colors in Direct Color Mode.
Invalid Aperture on NT
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.
XGA Display Adapter/A - Installation instructions
Installation of the XGA card is much like any other Micro Channel adapter.
First, simply place the card in a Micro Channel expansion slot. A 32-bit slot is preferred, due to the speed advantage. There is however one slot the XGA card will not fit, and that is the slot with the AVE. The XGA card does have an extension that looks much like the 8514/A extension; however, upon closer inspection you will see the extension on this card is positioned differently. The positioning of the XGA extension tab will prevent it from being inserted into the slot with the auxiliary video extension.
The XGA card only occupies 8KB of memory
between 640KB and 1MB. Since the XGA card is a Bus
Master, it can occupy any 8KB in the "C" or "D" range.
To see which part of memory is being used by the XGA
card, choose the menu option "Display Memory Map" from
the Reference Diskette. Another great feature of the XGA
card is that you can have up to six XGA cards installed
in one machine (five if the system has XGA already on
the motherboard, like the Model 90). To take advantage
of multiple adapters, software must be specifically
written to do so.
If you have an XGA card in a system that has VGA on the system board and a display attached just to the XGA card, the XGA card will function in VGA and high resolution modes. Now, if you have the same setup as before but a display is attached to the motherboard VGA port and another to the XGA card, all VGA (and lower modes) will be displayed on the display attached to the motherboard port. The XGA card will only be used when high resolution is required. You will not get an echo of a VGA image onto the display attached to the XGA port as you would using the 8514/A.
Once the card is installed,
the appropriate device driver must be installed before
the high resolution can be accessed. There are two
device driver diskettes that come with the XGA card. The
first diskette contains all of the device drivers for
DOS, Microsoft Windows 3.0, Microsoft Windows 286 2.1,
and AutoCAD Release 10. The second diskette contains
support for OS/2 1.2 (OS/2 1.3 ships with an XGA
AdapterId 8FDB XGA Display Adapter/A
Video I/O Address
1 MB VRAM Aperture Base
Removal of system memory may degrade system
performance. If aperture has been allocated an
address range and it results in a reduction of usable
system memory (with Micro Channel memory adapter)
then the aperture can be disabled.
Video Arbitration Level
ADPItem 1 ROM Address Range