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From: steve@bambi.UUCP (Steve Miller)
Newsgroups: net.graphics,net.micro.pc
Subject: Re: AT&T Graphics Boards Info--looking for review.
Message-ID: <517@bambi.UUCP>
Date: Fri, 5-Sep-86 15:17:25 EDT
Article-I.D.: bambi.517
Posted: Fri Sep  5 15:17:25 1986
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> One thing I'd like to know is whether or not the Targa-16 (or others)
> have colour lookup tables so you can do gamma correction - if not has
> ATT tried any kind of 'average' gamma compensation on the rgb outputs
> in the board design?

At present, none of the TARGA boards has a color lookup table.  EPICenter
tells me that this is being considered, at least for the TARGA-8.

> Also I assume the 512k of the 16 is not mapped in one window into the
> pc's addressing space - so how big is the window and how do you switch
> it?

My TARGA-32 allows access to two different 32k blocks, in a contiguous
64k address space.  The TARGA-24 is addressed identically, meaning that
that one out of every four bytes has no memory.  I don't know about the
TARGA-16 in this regard.

> What other parameters can you control on the board?

Because the TARGA-16 has an integral RGB/NTSC decoder, it also has
some registers that govern contrast and other video characteristics.
There's also zoom and scroll, of course.

> Is it possible to upgrade a 16 to the other (24,32) versions?

There is no provision for upgrading the hardware.  At present, I don't
believe EPICenter accepts trade-ins.  I think some gentle pressure is
in order here.  The software is another story.  The C source shipped with
the board is clearly intended to be independent of the particular TARGA
you are using.  I can't verify this by experiment, but the code looks
very well written to me; I expect one could modify programs to work with
various boards quite easily.  On the other hand, I have been tempted to
"go around" some of these routines, in the hopes of trading device
independence for speed.  I'll get back to you on this...


In case readers of this group can't already tell, I LOVE THIS BOARD!
It really is everything I need to create broadcast quality graphics.
The people at EPICenter (Brad Pillow, in particular) are nothing but
helpful, their advertising is accurate and the gadget does what they say.

Another recent hardware discovery of mine is a board that allows exact
frame-by-frame animation on some 3/4" and some 1/2" VCR's.  Anyone
want to hear about that?

	-Steve Miller Image Space Inc.
	              Suite #3
	              125 Washington St.
	              Hoboken NJ 07030
	              (201) 798-0429