ref: f02c92a5fb2d18e1248a67b15cd2ec7dcea2b4d7
dir: /sys/src/cmd/gs/lib/ras3.upp/
-supModel="SUN rasterfile, 3 Bit, 7 Colors (RGB-Ghostscript)"
-sDEVICE=uniprint
-dNOPAUSE
-dSAFER
-dupColorModel=/DeviceRGB
-dupRendering=/ErrorDiffusion
-dupOutputFormat=/SunRaster
-dupComponentBits="{1 1 1}"