Path: utzoo!attcan!uunet!cs.utexas.edu!uwm.edu!wuarchive!texbell!vector!attctc!chasm From: chasm@attctc.Dallas.TX.US (Charles Marslett) Newsgroups: comp.windows.x Subject: Re: x-window on pc Summary: Lets lot believe the ISC folk! Keywords: x-window, pc Message-ID: <10288@attctc.Dallas.TX.US> Date: 21 Nov 89 12:50:33 GMT References: <1370@ssc-bee.ssc-vax.UUCP> <1989Nov11.175220.25696@world.std.com> <1989Nov15.003835.4889@world.std.com> Organization: The Unix(R) Connection, Dallas, Texas Lines: 56 In article <1989Nov15.003835.4889@world.std.com>, madd@world.std.com (jim frost) writes: > chasm@attctc.Dallas.TX.US (Charles Marslett) writes: > >In article <1989Nov11.175220.25696@world.std.com>, madd@world.std.com (jim frost) writes: > >As a corollary, I have been trying to get support from any of the Unix > >vendors for 256-color X-windows drivers. None offered to provide them, > >but Interactive has been working diligently, > > The last time I spoke with the ISC technical people, they stated that > they didn't support 8-bit color because it was too slow. Having used > a Sun386i with 8-bit color, let me tell you that they're probably > right. A lot of optimization needs to be done to make it acceptable. > ISC seems to have done fairly well so far, though. The 256 color server I am currently working on is only a week from being 100% C code. It runs considerably faster than the original 16-color server for the VGA shipped with 386/ix in September. [It also runs a bit slower than the current "soon to be released" 16-color server that it should be compared against.] The screen-to-screen copy (bitblt) runs almost twice as fast as the new 16-bit server though (character output is about a third as fast, to balance things out). I think on average the VGA 256-color X11 server should run "almost" as fast as the 16-color server. And the individuals at ISC who have disagreed from the first simply do not "know" the VGA and its architecture [I DO!]. Though the 16-color mode often has twice the bandwidth of 256-color modes, and the 256-color modes have to shove twice the bits around, they involve lots of I/O (and in protected mode 286, and especially 386, code that slows everything down). I still have to stand by my statement that they are helping me a lot more than the competition (unnamed ;^). Even if they, generally, don't believe it can be done! > >On the other hand, I have tried several times to discuss what I have to do > >to support X11 in 8-plane mode, > > You shouldn't have to do anything special; you'll just have a pallette > of 256 colors to work with instead of 16 unless you're doing something > like colormap-based double-buffering. No . . ., try looking at the way the video memory is organized in the VGA 16- color modes, and how it is organized in the 256-color modes. An efficient server for one set of modes is not likely to be well organized for the other. Specifically, one is a heavy user of I/O instructions, the other cannot usefully take advantage of the VGA's internal latches. ETC. > Happy hacking, > > jim frost > software tool & die "The World" Public Access Unix for the '90s > madd@std.com +1 617-739-WRLD 24hrs {3,12,24}00bps Charles Marslett [a bad boy, at interactive now, since they told me to shut up, and I ain't] chasm@attctc.Dallas.TX.US (or some other reasonable facsimile)