On 19 September 2013 17:24, Nick Sabalausky < seewebsitetocontac...@semitwist.com> wrote:
> 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). > Atari 2600 was the only scanline renderer I know of from that time, and it certainly was made to be cheap! ColecoVision and SG-x000 were not affordable by comparison to the 2600. ColecoVision, Intellivision, Atari 5200, Atari 7800, NES, SMS (SG-1000 and friends), Genesis, Snes, C64, etc, etc were all tile renderers, and the first 5 items in that list didn't even have scroll-offset registers. 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.) > Do it, it's surprisingly easy, but jolly good fun :)