Graphics computer system having a second palette shadowing data in a first palette

A graphics processor system comprising:

• a graphics processor having a local data bus and a local address bus;
• a video memory storing color codes corresponding to a display, said video memory connected to said local data bus and said local address bus permitting said graphics processor to specify said color codes stored in said video memory;
• a palette connected to said video memory having a look-up table memory for recalling color data words corresponding to color codes received from said video memory, said palette connected to said local data bus and said local address bus permitting said graphics processor to specify said color data words stored in said look-up table memory;
• and
• an interface circuit connected to a host data bus, a host address bus and said palette, said interface circuit writing data on said host data bus into said palette upon detecting predetermined addresses on said host address bus.

In a graphics computer system including a host computer having a host data bus and a host address bus, a first video memory storing color codes corresponding to a display, a first palette having a first look-up table memory for recalling color data words corresponding to color codes received from said first video memory, a graphics processor having a local data bus and a local address bus, a second video memory storing color codes corresponding to a display, a second palette having a second look-up table memory for recalling color data words corresponding to color codes received from said second video memory, the method of operation comprising the steps of;

• employing said host computer to specify said color data words stored in said first look-up table memory via said host data bus and said host address bus;
• employing said second palette to specify said color data words stored in said second look-up table memory via said local data bus and said local address bus;
• detecting predetermined addresses on said host address bus, said predetermined addresses employed by said host computer for writing into said first palette;
• writing data on said host data bus into said second palette upon detecting said predetermined addresses on said host address bus, thereby causing at least a portion of said second palette to store identical data as stored in corresponding locations of said first palette.