Curious about ARII design considerations

HHaase

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I'm just flat out board right now, and am on a circuit board design kick lately. Looking at the ARII, it's flaws and quirks. Even considering re-designing them to modernize and eliminate the biggest flaws. Get rid of the sense circuit, design away the obsolete and unavailable components. Looks like there is a hell of a lot of them out there, so I wonder if there is any market at all for modern replacements.
 
I'm just flat out board right now, and am on a circuit board design kick lately. Looking at the ARII, it's flaws and quirks. Even considering re-designing them to modernize and eliminate the biggest flaws. Get rid of the sense circuit, design away the obsolete and unavailable components. Looks like there is a hell of a lot of them out there, so I wonder if there is any market at all for modern replacements.

I would like to do the AR1, but the Ar2 was physically bigger, and that put me off.

Some of them are single sided, and some are double sided.

Some people use a switching power supply to supply the voltages in their cabs. Sound amplification could easily be added too.

It would be great to see a plug and play power supply.
IE a total modern revamp, but with all the old plugs to make it easy for everyone
 
Yeah, that's the philosophy that I want to go with is that it will mount the same as the original regarding connectors and physical board size, but componentry would be fair game for a total redesign.

I would only consider a double sided board really, if for nothing else because fully thru-plated solder pads are more durable. I'm also wondering if maybe a split board would be a better choice. Meaning I'd do an ARI plus a separate sub-board that adds in the ARII specific components for the +12v, -5V, +/-22v. Makes more sense from a production standpoint, doing more stuff with less actual boards.

-Hans
 
I could use a Williams system 6/7 style heatsink that's elevated off the board, and only the side edges actually touch the board. Or you could throw a layer of fish paper under it.

Even better is If I can get it to work with a TO-220 format MOSFET instead of that TO-3 style, I can use a vertical heatsink. Lots of options in that case.

-Hans
 
Because of the number of variations on the AR boards, it might be good to compile a list of games that used them and the variation used in each game. I am sure there would be a fairly good sized market out there for replacements in the Pole Positions, Battlezones and Centipedes. But there were a lot of Atari machines made so there might be other games that either sold more or fry their ps boards more often.

I have thought that a base module with some way to snap in additional modules to cover the variations might be a cost effective way to go.

ken
 
Because of the number of variations on the AR boards, it might be good to compile a list of games that used them and the variation used in each game. I am sure there would be a fairly good sized market out there for replacements in the Pole Positions, Battlezones and Centipedes. But there were a lot of Atari machines made so there might be other games that either sold more or fry their ps boards more often.

I have thought that a base module with some way to snap in additional modules to cover the variations might be a cost effective way to go.

ken

Doesn't look like there was much variation between the ARI and ARII at all, at least from a board design perspective. A couple games had different components swapped in occasionally, but again the base ARI and ARII boards look to be universal.

Darren; That's a fantastic link, I'm going to spend a lot of time reading through there. Looks like Atari kinda forced the 'universal' ARII board on the designers, and they didn't really like the concept. Lots of hardware compromises they had to deal with, particularly with the audio circuits and speaker selection.

-Hans
 
Looks like you'd just need to implement -03 (the largest common denominator) and hope the other games' wiring harnesses don't care if the extra voltages are there.

Could be a big "hope" :)

Either that, or can just populate the boards as needed and label accordingly.

That's the good thing about doing repros of stuff this old..... the design envelope is pretty much fixed, so you don't have to plan for future expansion as much.

-Hans
 
Guys;

You all gave a lot of great info here. Time to get down to some serious research on this one, and I think I may have to start tapping into resources to find out the reality of what these games actually need. In all honesty, I am seriously considering making new ARII's, but IF it comes to actually making them it's probably 6 months away or so, I've got other projects that are at the assembly and shipping stage which are the priority right now.

For most of the board, I'm looking at probably just replicating the schematic of the audio and most of the voltages. Though i'll use radial caps instead of axials, not use disks when possible. I'll probably stick with linear regulators, I don't know how sensitive the audio system is to switcher noise in Atari machines, particularly being co-located on the same board.

How is the audio circuit on these usually? Any common issues or complaints other than static from the old caps?

Though the thought is running through my head about Pole Position. That may be something to consider a unique boardset down the road if it really causes that much trouble. I don't know much about the issues that occur with the dual ARII's in that setup though. More research fodder.

Dez;
If you want to shoot me a PM with the layout problem you're having, maybe a fresh look from an outsider can help out?

-Hans
 
Do you really think that there is much of a market for new AR PCBs considering the existing ones, though flawed, are easily modified?

(I have a about dozen of them I'm not using).

Darren Harris
Staten Island, New York.
 
Do you really think that there is much of a market for new AR PCBs considering the existing ones, though flawed, are easily modified?

(I have a about dozen of them I'm not using).

Darren Harris
Staten Island, New York.

That's one of the big questions, no doubt about it.

In time there will be further demand, as the LM305 5v regulator isn't available anymore. I don't see an NTE cross-reference for it either. But for now, there are a lot of them on the used market.

Though it hasn't hurt sales of pinball power supplies. There's piles of system 6 power boards out there, but the aftermarket guys still sell a lot. And that's a board that's currently fully supportable.... until the LM323's dry up.

-Hans
 
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