Abstract
Video display speed constitutes a very important factor in modern software performance. The best way to achieve fastest display is by accessing Video RAM and programming video card directly. In addition to the speed, this method provides flexibility and high performance video display operations. Besides that, dealing with 64K and 16.7 M color mode can be achieved only by this method. Fast Image Display (FID) software is developed to display two popular types of images (BMP, PCX) using direct access to VRAM method with various SVGA modes differing in resolutions and number of colors. Assembly instructions and C++ language have been used to write Software parts.
Highlights
As a general rule, the video display is created using eitherDOS or BIOS services that appropriate to the task in hand
BIOS supports capabilities to deal with at most 256 color modes, i.e graphics modes with more than 256 color cannot be managed by BIOS functions
Direct Access Display method Each video card contains an appropriate amount of memory called Video RAM (VRAM) that stores information related to each pixel appears on the screen
Summary
DOS or BIOS services that appropriate to the task in hand. DOS and BIOS provide several functions for display manipulation, these functions are slow because the mechanism used to call these functions is slow and call BIOS interrupt takes much longer than a routine within a program. [1][7]. Direct Access Display method Each video card contains an appropriate amount of memory called Video RAM (VRAM) that stores information related to each pixel appears on the screen. Address calculation for a pixel depends on the number of bits required to represent each pixel and the organization of VRAM, which differs in each graphics mode. This method begins by setting an appropriate mode and calculates pixel address, change its color. Accessing VRAM in 256-color mode According to the organization described, each bitplane is addressed individually, so all pixels are not available in the 64K byte at A0000h at the same time.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: AL-Rafidain Journal of Computer Sciences and Mathematics
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
