Emc vs modern lcd monitors

gene heskett gheskett at wdtv.com
Mon Aug 15 16:05:42 PDT 2011

On Monday, August 15, 2011 07:01:27 PM Felix Miata did opine:

> On 2011/08/15 18:16 (GMT-0400) gene heskett composed:
> > On Monday, August 15, 2011 06:07:09 PM Alex Deucher did opine:
> >>>> gene heskett wrote:
> >>  >>  >  One of the problems that was confusing me recently is that I
> >>  >>  >  had replaced the old samsung crt monitor with a much newer
> >>  >>  >  cheap AOC lcd that runs at 1360x724 at best, but under the
> >>  >>  >  vesa driver on an ati x1650 video card, it apparently is
> >>  >>  >  running in 1024x768. آ This results in a pixel that is far
> >>  >>  >  from square unless I use a button on the monitor which
> >>  >>  >  shrinks the display sideways, leaving 2" wide black stripes
> >>  >>  >  on the sides.
> >>  
> >>  The problem with vesa is that you are limited to standard vesa modes
> >>  that are implemented in the vbios.  You cannot define arbitrary
> >>  modes.
> >>  
> >>   For that you need to use a real driver specific to your video chip.
> > 
> > I was afraid of that Alex.  And I tried some Modelines suggested on
> > the EMC mailing list&  got thrown under the bus just as it was
> > leaving.  This application that must run, is a realtime application
> > with a base loop of its i/o running every 20-40 u-secs.  _NO_ "real"
> > driver allows that, wrecking carving of parts in wholesale numbers
> > because the IRQ's that drive this apps base thread can be locked out
> > by the "real" driver for intervals in excess of 100 milliseconds. 
> > The 'vesa' driver is the only driver that allows the base thread to
> > keep some semblance of a steady beat.
> > 
> > This particular card is an ATI X1650.  Does it perchance have an
> > available vesa bios update that would add some of the 16x9 modes like
> > this?
> If
> http://en.wikipedia.org/wiki/VESA_BIOS_Extensions#Modes_defined_by_VESA
> is any guide, I'd be really surprised if anyone anywhere found any
> video card of any age that provides BIOS support for the abortion that
> are the 136Zx7zz modes found only in lower cost widescreen desktop
> displays. If you were to spend a bunch of money on lots of video cards
> you might find something with some amount of 16:9 or 16:10 support, but
> not likely 136Zx7zz would be any of them.
> I noted the keyword "cheap" above in reference to your new display. If
> cheap is what you're after for your VESA environment, I suggest going
> back to one of the readily available CRTs that are so hard for most
> people to give away, or replace that new widescreen with a new 4:3 LCD
> display.

Chuckle, rotsa ruck finding one of those without mail ordering it & putting 
up with a 40 day back order because they have to get one of those from 

As for the crt, that's 4x the power and weight.  and dying like flies 
around here.  That old Samsung that smoked was may last tube monitor & 
getting fuzzy when it let all the magic smoke out.

Cheers, gene
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