🚀 go-pugleaf

In article <6583@shemp.UCLA.EDU>, ex499mih@CS.UCLA.EDU writes:
>  The User (program) selects one graphics color which the hardware will
> consider to be "transparent" to video. As the EGA is "read" during refresh,
> any pel which is to have the same value as the transparent color is given 
> the ntsc signal at that time (i.e. EGA goes to the display until transparent
> color, if = transparent color then NTSC).

Wow, what a novel concept!  :-)  Suppose IBM will try to patent it?

But seriously.. this sounds just like a digital form of chroma keying.  (I
even seem to remember someone suggesting chroma keying as a solution to the
original poster's problem.)

Question for all you serious broadcast people out there: I imagine the
original chroma key hardware was analog.  Is it still done that way, or is
it done digitally now?  Seems to me that with these new-fangled digital
video controllers stuff like this would be getting much simpler, if not
cheaper...

...!decvax!decuac!\                                               Phil Kos
  ...!seismo!mimsy!aplcen!osiris!phil           The Johns Hopkins Hospital
...!allegra!/                                                Baltimore, MD