The integrated video subsystem supports all video graphics array (VGA) modes and is compliant with super video graphics array (SVGA) modes and Video Electronics Standards Association (VESA) 1.2. Some enhanced features include:

Integrated video subsystem on chip, including 2D, 3D, and video port

66 MHz AGP system bus interface with 2X and 4X

Sideband signaling (some models only)

Command list bus mastering support for fast 2D and 3D performance

64-bit, 125 MHz SDRAM or 166 MHz SGRAM interface

Plug and Play support

4 MB dynamic display cache memory

Advanced Power Management (APM) support

Color space conversion

Hardware scaling

The integrated graphics memory controller subsystem complys with the VESA Display Data Channel (DDC) 1.1 standard and uses DDC1 and DDC2B to determine optimal values during automatic minor detection.

The video subsystem has the following resource assignments.

Table 2. Video subsystem resources

Resource

Assignment

 

 

ROM

Hex C0000-C7FFF (32KB)

 

 

RAM

Hex A0000-BFFFF (standard VGA frame buffer)

 

 

I/O

VGA, sequencer, CRT controller, graphics controller, attribute, RAMDAC,

 

extended sequencer, extended CRTC registers

 

 

IRQ

PCI interrupt 1 (enabled by default in the Configuration/Setup Utility

 

program. Normally assigned to IRQ 0B when nothing else is installed in

 

the system. 3D systems use this interrupt.)

 

 

DMA

None, N/A for AGP bus

 

 

For further information on resource assignments, see “Appendix B. System address maps,” on page 47 and “Appendix C. IRQ and DMA channel assignments,” on page 53.

Chapter 2. System board features 9

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IBM PC 300GL manual Video subsystem resources Resource Assignment, Rom, Ram, Irq, Dma