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Re: Radical Video Idea

To: pyramid.com!riscy@informatik.ee.edag.de
Subject: Re: Radical Video Idea
From: peter katzmann <PET@informatik.ee.edag.de>
Date: Tue, 29 Jun 1993 15:53:24 CET
Priority: normal
Reply-to: pet@informatik.ee.edag.de
> Is it a reasonable thing to ask of a 3041 to generate a signal for 
horizontal
> and vertical retrace?  For 1024x768 at 70 hz you need to generate 
53,761 
> retrace signals per second all that have to be accurate within a 
minimum of 1/
> (1024*768*70) = 1/55,050,240 of a second.  Which gives you one 
pixel accuracy
> 
> Isn't that an easy thing to do directly?  I think using a second 3041 
just
> for an Xserver is a great idea.  Handling keyboard I/O, serial I/O 
seems
> fairly direct.  Handling time critical video retraces sounds like it's 
> not but then I'm in software..... 
> 
> This would make better use of the main's cpu ram, cache, cycles, 
context
> swiches, memory bandwidth for running linux or applications.  The 
secondary 
> processor would worry about I/O and running the Xserver.   I'd say 
of
> all those things we are shortest on cache (most comprable 
machines have
> 128 k cache).
> 
> If this become impracticle maybe we should add a 256 k cache 
instead.
> 
> This way we get the advantages of an X11 specialized accelerator 
(directly
> implements all of the Xprotocol) without the disadvantage of porting
> X11 to a unsupported chipset.  You only need to learn one chip 
instead of 
> two.  X11 should compile fine on a mips chip, as well as gcc.
> 
> Basically if the hardware guys can put it together it should be great.
> 
I like the Idea, but what about the cost's. You have to add over $100 
for the second CPU. 
I don't like the Idea to make the timing signals from the CPU. it's to 
critical, and i don't think it will bring us a big boost. In this cas better 
lets look about an MIPS 2000 for Graphics acceleartion and i/o and a 
simple design for the video control hardware

peter

----

EDAG-Fulda | P. Katzmann | E-Planung | Steinauer Str.| 6400 Fulda
tel. 0661/6000-454/464 | W. Germany | in: pet@informatik.ee.edag.de

 

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