On Fri, Jul 16, 2010 at 4:54 PM, Michael B. Smith <mich...@smithcons.com> wrote: > When the Amiga first came out, it featured a HAM (Hold and Modify) graphics > mode that supported 4,096 colors plus alpha. At the time, that was huge.
Never heard of it. Looked it up.[1] Wow, what a brilliant hack. Briefly, the video generator was capable of 12-bit color, but the system didn't have the memory bandwidth that would have been needed to back a full color image. So each pixel is divided into R, G, B components, and each pixel is defined in terms of the difference of *one* of those components vs the previous pixel. This imposed certain constraints (sharp horizontal color changes had artifacts, and moving sprites are practically impossible), but it gave the machine a 4096 color display on much cheaper hardware. [1] http://en.wikipedia.org/wiki/Hold-And-Modify -- Ben ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
