I got a question in the YouTube comments about the sine tables that we used for a few animations, like the Copper Bars, the Smooth Scrolling etc. In this episode I try to explain why and how to create sine tables. The idea is to speed up computations, since computing the sine or cosine — even with an FPU — takes an awfully long time on early MS DOS machines.
In the last live stream we did some Turbo C inline assembly, which was pretty fun. But let’s today use an actual pure assembler: the Borland Turbo Assembler. And let’s demystify some of the things surrounding assembly language. It is actually not that hard, so let’s write a hello world program, using assembly, for MS DOS!
Today we continue on our quest to make a small VGA game. So far we learned how to initialize Mode X and use some of its nice features. Copying images from system memory was painfully slow though. So let’s make it faster with a small trick!
The next part in the series about VGA Mode X programming. Let’s do some smooth scrolling. We already did that in text mode, but not in graphics mode, and not in a horizontal direction. So let’s lay down some basics!
Today we’ll tackle a more complicated topic. That’s also why the video is rather long with 40 Minutes. However I think this is necessary, given the importance of the topic. The VGA card is surprisingly feature rich. However a lot of these features are not accessible from the standard 256 color mode 13h. That’s why we take a look at Mode X today, which unlocks such features as page flipping, scrolling and giving access to the VGA’s full memory.