Category: Atari
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Quadrature Encoding Refresher
Quadrature Encoding …is the method used by mechanical mice, trackballs, and spinners like those used on Tempest and Arkanoid. It works by attaching a movement axis to a slotted wheel and placing the slots in between two optoisolators or optos. When talking about Quadrature Encoding, the two signals from the optos are sometimes referred to…
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Newest Version of AR-II Documentation
Atari Regulator/Audio II (AKA the A/R-II) Version -02 Information By James R. Twine (jtwine@jrtwine.com) ©2009-2026 Latest version available online at https://www.jrtwine.com/blog/?p=590 References and Source Material Information is this document is from personal experience with these beasts, and some was stole^H^H^H^H^H… um, I mean… inspired… from many sources including official Atari docs (wiring diagrams, schematics)…
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Can you “Bulletproof” an Atari AR-II Power Supply? I Think I Can…
Well, like the title initially asks, can you really “bulletproof” an Atari AR-II board? From what I have found on the Internet, and older material like Star Tech Journals, the answer really is no. Pretty much all sources that mention “bulletproof” and “AR-II” on the same page are only taking about performing the Sense mods,…
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WG6100 w/Tempest Showing a Tangled Mess in the Bottom Right Quadrant
So this is basically the second part of a previous post about a tempest that lost deflection. After running for a while that Tempest’s display changed into something that can only be described as a tangled mess: That is something that I never had seen before. The owner turned the game off and back on…
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WG6100 w/Tempest Showing a Multicolored spot in Center of Screen
So I was helping a newly minted arcade game owner when his first purchase, which is his favorite arcade game: Tempest. Shortly after getting it the X-Size pot fell apart and the game ended up only showing a Multicolored spot (larger than a just a “dot”) which changed depending on what the game was doing. …
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Watchdogging and Corrupted Centipede (Bad POKEY)
Got to work on a busted Centipede that booted to a white background screen that briefly showed the start of the attract mode (things drawn in green or purple) before crashing, watchdogging and doing it all over again. Test mode would do the same thing as well. Disabling the watchdog (by grounding the WDDIS test…
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Dig Dug with Floating Pins
Going through my boards, I came across a second Dig Dug board. This one boots to static garbage and no sound. Watchdog is barking. Removing one of the CPUs gets different garbage. Tried replacing with a known good one, no change. Checking the pins shows me that a couple of the data lines, from…
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Centipede Cocktails — Cocktail #2
My previous post, about Cocktail #1, clearly documents the “easy one.” This second one is gonna be another story. It has a very dead monitor, and a non-functional board. I have not yet benched the monitor, but it has no neck glow, which is never a good sign. The board has problems, but at least…
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Centipede Cocktails — Cocktail #1
Well, I ended up taking two Centipede cocktails off of another local collector as a package deal. Still want that Gorf, though… Will have to come back to that one soon! But I digress… So I have two Centipede cocktails here. One of them has a dead monitor (and a non-working board, I later discovered),…
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Sprint 2 – Stiff Steering and Hard Shifting
Problem: Stiff spinning steering modules and hard shifting between gears (Quick little story – while bringing this beast into its location, I fell and got pinned under it for a few minutes. It is amazing how much having your chest compressed effects your ability to call out for help! 🙂 OK – onto the next…