Home-brew Atari TT ECL VGA Adapter

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Icky
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Joined: Sun Sep 03, 2017 10:57 am
Location: UK

Home-brew Atari TT ECL VGA Adapter

Post by Icky » Wed Dec 27, 2017 7:53 pm

Today I had a go at building an Atari ECL (TT-High) to VGA adapter using the diagrams on the Atari-forum http://www.atari-forum.com/viewtopic.ph ... CL#p286175

I used the option suggested by Frank Lucas at the bottom of the thread to use diodes instead of the resistors on the monitor RGB lines.

Built it using break-out boards for the surface mount components and used a breadboard for testing. It works well apart from a few horizontal lines but if I clean up the circuit it should improve.

Below is a pic of the Atari TT connected to my makeshift circuit
IMG_2672.jpg
IMG_2672.jpg (2.31 MiB) Viewed 445 times
Running X on NetBSD at TT-High. See thread on running NetBSD viewtopic.php?f=18&t=398&hilit=NetBSD
IMG_2675.jpg
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tuxie
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Joined: Thu Aug 24, 2017 11:51 am

Re: Home-brew Atari TT ECL VGA Adapter

Post by tuxie » Thu Jan 11, 2018 3:22 pm

We adapted the DE signal from the shifter to bring it 1:1 on the Screen that means the most display is stretching the screen to 1280x1024 so the screen looks terrible. We put a CPLD into the DE signal and some other signals so on top and bottom is a black field now. The picture is very sharp.

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Icky
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Joined: Sun Sep 03, 2017 10:57 am
Location: UK

Re: Home-brew Atari TT ECL VGA Adapter

Post by Icky » Fri Jan 12, 2018 9:14 am

tuxie wrote:
Thu Jan 11, 2018 3:22 pm
We adapted the DE signal from the shifter to bring it 1:1 on the Screen that means the most display is stretching the screen to 1280x1024 so the screen looks terrible. We put a CPLD into the DE signal and some other signals so on top and bottom is a black field now. The picture is very sharp.
Very interesting - Sounds like a good way to get this rock solid on todays monitors. Are you planning on producing a purchasable product of your design?

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