cgtwelve is a 24-bit SBus-based color frame buffer and graphics accelerator, with 12-bit double buffering, 8-bit colormap, and overlay/enable planes. It provides the standard frame buffer interface defined in fbio.4s paired with microcode which can be downloaded using gpconfig.8 Application acceleration is achieved using the Pixwin and SunPHIGS Application Programmer Interfaces (APIs).
The cgtwelve has registers and memory that may be mapped with mmap.2 using the offsets defined in <sbusdev/cg12reg.h>.
When in double-buffer mode, each channel is dithered to 4 bits, yielding 12-bit double-buffering.
Created by unroff & hp-tools. © by Hans-Peter Bischof. All Rights Reserved (1997).
Last modified 21/April/97