CHRISTY@syr-nmr-aos1.CSNET (Lynx) (03/16/87)
Does anyone out there have X running using color on a Sun 3/110???
Our lab is having some problems....any help would be greatly apreciated.
Christy Russellmayer@rocksanne.UUCP (03/20/87)
Our group is acquiring a number of 3/110C machines, and we are interested in running X on them. I have been following the discussion, and have some questions about the 110C frame buffer organization and how it affects the X implementation. *** MY IMPRESSION *** of the 110C, is that it is really sort of a "1 1/2" frame buffer machine (please correct me if I am wrong). In addition to an eight bit deep lookup table driven color frame buffer, the machine also has a single pixel deep "text" black and white frame buffer. A "control" bitplane is used to select which buffer will be displayed (note: I do not know whether the control plane selects between the two buffers, or whether it masks the color buffer). I suspect that the SUN engineers who designed the machine found that: 1. Most color graphics (line drawing, etc.) were easier with an 8 bit contiguous pixel frame buffer organization (I assume SUN uses contigous pixels... If they used stacked color planes, the control plane would be unnecessary). 2. Doing text with a contigous pixel buffer was too slow. 3. 2 megabits (256K) of memory for the B/W buffer and control plane was cheaper than putting in high powered hardware. If my understanding is correct, then the real question is "how can the X server best make use of the 110C hardware". All of the notices I have seen so far appear to address the question "how can we get the X server to draw in color". Now, with some clever programming it should be possible to mask the architecture under the PIXRECT library. If SUN has done this, then they have already solved the first order problem. If not, then something needs to be done on top of the PIXRECT library. If PIXRECT already masks the hardware, then the questions becomes: 1. What assumptions does PIXRECT make and how do they interact with the X11 implementation? 2. Does SUN (though the "emulation modes") allow access to the different frame buffers. 3. How could the V11 server (no reason to work on V10.4 unless performance is really bad) take advantage of the architecture. For example, one of the features of V11 allows a pixmap depth to be specified for a window. An obvious approach would be to special case a one bit deep window with no color map. Would this give a performance boost for text windows? Would it be worth while trying to model the machine as a ten bit deep buffer with a strange, partially fixed, color map? -- Jim -- (Grapevine) mayer.wbst (Arpa) mayer.wbst@Xerox.com (NS) mayer:wbst128:xerox (Phone) (716) 422-2496 (UUCP) rochester!rocksanne!mayer