Porting MS-DOS Graphics Applications
By waiting for the VGA retrace, we are telling the program to wait until the monitor's electron beam reaches the bottom of the screen. Since there is a short pause before it jumps back to the top, it is a good moment to switch palettes without seeing “rainbow colors”. Thus, before switching palettes, we should wait for the VGA retrace as follows:
while (!(inportb(0x3da) & 8)); while ( (inportb(0x3da) & 8)); vga_waitretrace();
The following code assumes you have a character array of 768 values, representing the RGB values for 256 colors. For example:
char palette; where palette = R value of color 0; where palette = G value of color 0; where palette = B value of color 0; ... for (i = 0; i < 256; i++) vga_setpalette(i, palette[i*3], palette[i*3+1], palette[i*3+2]); outportb(0x3C8,0); for (i = 0; i < 768; i ++) outportb(0x3C9, palette[i]);
After adding SVGALIB code to the program, it's time to compile. Simply compile with the -lvga option to link the SVGALIB library. This library is preinstalled on most Linux systems; thus, if you experience problems linking it, you probably don't have it installed and should download it.
jaw3d was programmed by the author and is a Nullsoft Inc. product. Other cross-platform applications may be obtained at http://www.nullsoft.com/.
Jawed Karim is a freshman computer science student at the University of Illinois at Urbana-Champaign and works part-time at the National Center for Supercomputing Applications. His hobbies include programming and bicycle road racing. He can be reached at email@example.com.
|Speed Up Your Web Site with Varnish||Jun 19, 2013|
|Non-Linux FOSS: libnotify, OS X Style||Jun 18, 2013|
|Containers—Not Virtual Machines—Are the Future Cloud||Jun 17, 2013|
|Lock-Free Multi-Producer Multi-Consumer Queue on Ring Buffer||Jun 12, 2013|
|Weechat, Irssi's Little Brother||Jun 11, 2013|
|One Tail Just Isn't Enough||Jun 07, 2013|
- Containers—Not Virtual Machines—Are the Future Cloud
- Non-Linux FOSS: libnotify, OS X Style
- Linux Systems Administrator
- Lock-Free Multi-Producer Multi-Consumer Queue on Ring Buffer
- Validate an E-Mail Address with PHP, the Right Way
- Technical Support Rep
- Senior Perl Developer
- UX Designer
- Introduction to MapReduce with Hadoop on Linux
Free Webinar: Hadoop
How to Build an Optimal Hadoop Cluster to Store and Maintain Unlimited Amounts of Data Using Microservers
Realizing the promise of Apache® Hadoop® requires the effective deployment of compute, memory, storage and networking to achieve optimal results. With its flexibility and multitude of options, it is easy to over or under provision the server infrastructure, resulting in poor performance and high TCO. Join us for an in depth, technical discussion with industry experts from leading Hadoop and server companies who will provide insights into the key considerations for designing and deploying an optimal Hadoop cluster.
Some of key questions to be discussed are:
- What is the “typical” Hadoop cluster and what should be installed on the different machine types?
- Why should you consider the typical workload patterns when making your hardware decisions?
- Are all microservers created equal for Hadoop deployments?
- How do I plan for expansion if I require more compute, memory, storage or networking?