On Wed, 18 Sep 2013 13:31:48 -0700 "H. S. Teoh" <hst...@quickfur.ath.cx> wrote: > > I remember in the old DOS days, some games would load up custom > graphics into the video card's text font buffer, so that they can > draw sprites just by writing the corresponding characters into the > video card's text buffer. You can get very fast drawing rates since > the video card does most of the work for you (and you only need to > transfer 1 byte per 8x8 block of pixels instead of 8 bytes or more). >
That's essentially the same strategy behind the graphics hardware in most 8/16-bit consoles. Basically the ones from around SMS/NES and then up until 3D. You can identify them from the grid-based layouts (which were a huge improvement, for both gamers *and* developers over the "carefully time your opcodes to adjust the scanlines while they're being drawn" used by Atari VCS/2600 and, I'm guessing, probably the ColecoVision and SG-1000, which is what make them so amazingly affordable at the time). In DOS, a lot of CGA/EGA/VGA games used a similar approach as DOS-text-mode/NES/SMS/etc, but it had to be done in software. Obviously in those cases it didn't reduce the amount of data sent to the video card, but it did still reduce (significantly) the amount of HDD and RAM required to store the levels, and it somewhat simplified/reduced the amount of processing needed to render. (I've done a bit of old-school homebrew, and got my real coding start in DOS VGA gaming. Fascinating and incredibly fun stuff to develop for. I'd love to design/build my own tile-based console someday, just for the heck of it.)