Date: Mon, 17 Feb 1997 21:00:50 -0800 From: jehamby@lightside.com (Jake Hamby) To: ccsanady@nyx.pr.mcs.net, jdc@xinside.com Cc: FreeBSD-hackers@freebsd.org, FreeBSD-current@freebsd.org Subject: Re: pcvt/132 columns Message-ID: <199702180500.VAA00752@lightside.com>
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Jeremy Chatfield wrote: > Chris Csanady wrote: > > > > Just a thought, but what about using some sort of generic frame buffer driver > > in the kernel. <snip...> > > I'm not sure, but I think that netbsd has something like this for sun and some > > other architectures, and also a generic console that uses it. I suppose X must > > also have some of the necessary code as will if they work together. > > > > For what its worth, > > chris > > [reasons why this would be really slow] > > Thanks for the suggestions though. It would certainly make our lives > simpler if everyone was happy with plain framebuffer performance! Having seen the Sun console frame buffer on the older SPARCstations (like the SPARCstation 2), I am absolutely positive you don't want that on the PC! The problem with the Sun console, that Jeremy didn't mention, is that the frame buffer doesn't actually have a built-in text mode, like VGA cards do. The nice thing about VGA is that the CPU only needs to send ASCII characters to it, an order of magnitude less information than sending font bitmaps to it (and also much simpler). The worst part about the Sun, though, was that there's actually an OpenBoot FORTH (in other words INTERPRETED) program in the card's ROM which is used to draw the characters out to the screen, leading to painfully slow speeds (slower than even a 9600 baud terminal on the SPARC 2's) and tremendous CPU utilization, although it seems that NetBSD and Solaris manage to speed up the console somehow, compared to SunOS (NetBSD actually has a "RASTERCONSOLE" in the kernel, which probably has something to do with it). The end result is that in many cases, when bringing up one of the older Suns, it is FAR faster to get X running, or rlogin from another system, to edit the /etc files, than to suffer through vi running on the framebuffer console! -- Jake
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