From: dstamp@watserv1.waterloo.edu (Dave Stampe-Psy+Eng)
Subject: TECH: Re: Driving NTSC displays
Date: Tue, 4 Feb 1992 14:11:40 GMT
Message-ID: <1992Feb4.141140.12631@watserv1.waterloo.edu>
Organization: University of Waterloo


cks@zycor.lgc.com (Chris St. John) writes:

>dstamp@watserv1.waterloo.edu (Dave Stampe-Psy+Eng) writes:
>
>> Here's a suggestion ... use something like my REND386 package and a
>> simple added crystal on a VGA card, to drive NTSC displays or LCD
>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> panels DIRECTLY at a cost of $100 or so.
>
>This, and another reference from Dave Stampe I could not find, (maybe
>it was on the glove list) mention driving NTSC displays "directly". I
>don't know what this means, or how to do it. Is this something a
>person with a "paint by numbers" level of hardware experiece could do?
>Or easily learn to do? If it is easy, could someone explain? I seem to
>remember someone mentioning that it was possible to increase the
>number of scan lines while doing this.

Depends on what you're driving with the card.  The added crystal
can be put on the feature connector, but I'm not sure if power is
available there (I soldered mine to the board).  I also use 3 VGA
cards in my computer, but the mods to do this are not trivial.  IF
there was a big demand I might look into modifying cards, but I
hear rumors of a lowcost NTSC graphics card for the PC in a few months.

The software is fairly simple, but determining the register values 
is trial-and-error.  I have code to drive Sharp LCD panels ($400-800
each) with the VGA card, and some to drive B&W TV's (But they're
modified to use direct sync inputs).  Actually, I'm reducing the number 
of scan lines to get a faster video frame rate.

I could distibute the code, but it's not liable to do much good without
the crystal or such.  I may look into something later on (few months)
to package the know-how and post it, but have noo time right now.  If
you find someone willing to do the mods, that would make it easier.


--------------------------------------------------------------------------
| My life is Hardware,                    |                              | 
| my destiny is Software,                 |         Dave Stampe          |
| my CPU is Wetware...                    |                              | 
| Anybody got a SDB I can borrow?         | dstamp@watserv1.uwaterloo.ca |
__________________________________________________________________________