ref: 3b82afa72f80a73ea1a801cd1ff3def12cb0bc1d
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}"