Interview with Atari VCS 2600 PureVideo VEC Module CreatorsPosted: February 26, 2015
Last year I covered converting the VCS 2600 for composite video, replacing the aging RF output which many new televisions struggle with. The results were mixed, the picture was significantly better then it had been, but it still suffered from interference. Some months later I learned about the PureVideo VEC Module developed by Amibay users “Bluesbrothers” and “TC”. Two chaps who like me, were not happy with the picture quality of their 2600 and wanted to offer a better solution to fellow Atari enthusiasts.
Thus was born the PureVideo board, a professional looking, easy to install mod, compatible with the Six switcher woody to the Atari Junior. I bought one of these boards and have to say they are the MUST have mod for your VCS 2600. They make using a modern flat screen telly a painless experience!
I caught up with the pair last year and pick their brain about the PureVideo module and story behind it.
Q1. What spurred you to develop the Purevideo VEC?
Bas: An order of 25 units which became 50, didn’t think for one moment there would be a further order of 200 units including a major revision for NTSC compatibility.
The challenge was set by Rob, and I went away to see just what we could cook up.
Rob: I’d been frustrated for quite some time that a drop in solution didn’t exist and that the hacks which were know about on the internet all seemed complicated, destructive to the PCB and none gave consistent results with every 2600 variant. I felt it was time for a proper consistent solution and so the hunt started for a proper engineer to tackle the problem.
I was always confident that this unit would sell in high numbers as long as we got it right which I believe we did though it took some effort to convince Bas that anyone would go out and buy this. I’m very pleased to say I have changed his perception on this completely and I don’t anticipate that the next order will last long once we put the product on general realise (we have kept it low key until now) and the revision to encompass NTSC compatibility should see a successful launch Stateside in August I hope
Q2. Were there any technical challenges in designing a board that not only worked with every 2600 console but also work with modern televisions?
Bas: There was no real challenge regarding the different 2600’s as long as the design stayed close to the TIA chip as this is a common device in all these different variants.
The brief I set myself however was simple;
- Minimal intrusion on the original console, i.e. invisible.
- No hard modifications to the PCB
- Simple drop in, plug and play concept.
- Blend in with the original pcb.
- Totally reversible.
- Consistent performance, no fine tuning.
- Allow RF operation to be easily available.
The above points were very important as some versions of the 2600 are quite rare and expensive…
Rob: For me the problem was finding someone who would actually follow through with the brief both on time and as closely as possible to the original brief only making changes for the better rather than to save costs or effort. It took several attempts to find someone who’d follow it through to the end before Bas got involved.
The module had to be easy to fit (for someone competent at soldering),… no complicated altering of resister ladders or cutting tracks.
No defacing of the machine itself – People like their toys but they also, on the whole, want a machine that hasn’t been butchered
The module had to give the same performance in every version of the 2600
Q3. BMV has delved in to modifying the VCS for composite in the past, how is the Purevideo VEC board different to the video hacks / mods that currently exist on the internet?
Bas: The VEC2600 is an original solution, unique in the way it is fitted compared to internet hacks.
Careful and in depth calculations were made on paper first to ensure the correct luminance mix network and also to ensure marginal current had to be provided by the TIA..
The final Amplifier stage biasing was calculated to provide a linear output across the bandwidth and allow sufficient headroom so as not to clip the waveform, it also provides a slight lift to the black level to overcome the compression effect that LCD panels display in the darker region.
Even though the display on the oscilloscope was technically perfect, final manual tweaks were carried out to the biasing so that my eyes were happier than the scope.
It’s a testament to the amount of work that went into the design that when we trialled NTSC consoles we found no adjustment to the circuit was necessary at all.
Due to the method of install chosen it was decided to implement the module using surface mount technology, this has many advantages, mainly the noise performance remains very low and signal loss is minimised due to the short tracking and large Ground planes. The next revision actually uses even smaller surface mount components. The biggest benefit however is the module is manufactured easily offshore at a good cost ratio.
Rob: I’ll leave the tech explanation to Bas here but as Bas has said the solution needed looking at from a time served engineers point of view rather than one of an enthusiastic hobbyist and his knowledge in understanding the proper calculations gave us a solid starting point from which to begin rather than using a trial and error approach. It also needed to be driven to some extent by myself as regards the view point of the average consumer, it needed to be as simple as possible to implement whilst slick and professional in design.
Q4. How hard was it to take the idea in your head and turn it in to reality?
Rob: For my part the hardest thing was finding the right man to help me develop this and then (and he won’t mind me saying this and I often joke about it) feeding info in such a way as to make him believe he’s come up with the ideas.
One of the real bonuses to come out of this is a friendship and understanding another that has led us on to developing more stuff together and expect to see more products from the two of us in the near future
Q5. As we are on the subject of the Atari 2600, what is your favorite memory / game?
Bas: Indy 500 and Missile Command…
Rob: For me it’s Breakout because Pong/Breakout style games were just the thing back in 1980 which is my first memory of gaming and Space Invaders because where my Mum worked in a pub they had a Space Invaders machine and I was able to spend endless hours perfecting my alien blasting technique. Both games just remind me of being young and carefree. Happy times!
I’d like to thank Rob and Bas, aka Bluesbrothers and TC for participating in this interview and giving us all and insight in to this lovely piece of kit!