Video Memory; Video Modes - HP Vectra VL5 4 Technical Reference Manual

The video subsystem uses the PCI bus for data transfers between the processor and the video
subsystem, and has the following features:
• 100% compatible with IBM® VGA display standard
• 32-bit video memory access with 1 MB DRAM. This increases to 64-bit access when an
additional 1 MB DRAM is installed
• Hardware acceleration of graphical user interface (GUI) operations
• Support for up to 2 MB DRAM at 60 ns
• Graphics resolutions of up to 1280 x 1024
• Integrated 24-bit RAMDAC
• Green PC power saving features
• Standard and Enhanced Video Graphics Array (VGA) modes
• DDC 1 compliant.

VIDEO MEMORY

The S3 Trio 765 64V+ integrated video subsystem has 1 MB of video DRAM preinstalled on
the system board, and provide two sockets for the installation of a pair of 512KB video DRAM
chips, giving a total of 2 MB video memory.

VIDEO MODES

The video subsystem is responsible for generating video data (which is placed in video
memory) to be sent to the display.
The following table details the standard VGA modes which are currently implemented in the
video BIOS. These modes are supported by standard BIOS functions; that is, the video BIOS
(which is mapped contiguously in the address range C0000h to C7FFFh) contains all the
routines required to configure and access the video subsystem.