possible Tetris PCB project (pics included)

Thread in 'Hardware' started by R McNally, 9 Apr 2015.

  1. Greetings, all. This is my first post here, so thanks for reading. I have an Atari Tetris PCB that I got years ago and always wanted to use, but didn't have room for a third cabinet (I have an Arkanoid minicab and a Ms. Pac cocktail with a 48-in-1 board). So, I thought about making a table-top unit that could be easily moved around. As a sidebar, I do not have the required components I would need for this project (power supply, harness, control panel items, etc.). If it turns out that the project is feasible, I can work on that.

    I lost my job last month, and while trying to find a new one I've been working on long-outstanding projects around the house. Recently I helped a friend with some spring cleaning and came home with a Brother WP-510 word processor equipped with a small 5x9 monochrome monitor. The unit did not work when I turned it on, although I did see screen flicker when I powered it on. I disassembled the unit and removed the monitor and its chassis; photos of both are attached. Finding the Brother monitor, and having some free time, is what caused the Tetris idea to pop back into my head.

    What I want to do is to use the Brother monitor with Tetris board. I am aware that it's a monochrome monitor, so I do understand that if this does work the game will not be in color. Although I'm fairly comfortable around electronics, basic soldering, and safe monitor/chassis removal (I've removed the Arkanoid's chassis to have it recapped twice), wiring monitors is new to me. That's why I figured I'd come here to see if anyone else had a similar project. I did run across Metallian's project, which is what prompted me to join: http://tetrisconcept.net/threads/atari-tetris-arcade-build.2357

    Question #1 of 2: anyone have any idea whether this would work with this monitor? Clearly my main challenge is getting guidance regarding how to connect the monitor chassis to the JAMMA harness, which is why I included photos of the monitor yolk.

    Changing subjects slightly, several years ago I posted on rec.games.video.arcade.collecting and asked about the Tetris manual's mention of specific power requirements, and got "Reply #1" below. Then I saw something very similar, which I'll call "Reply #2" below. As you may know, page 1-1 of the Tetris manual (I found a digital copy on http://basementarcade.com/arcade/library/manuals/t/) details the specific power requirements, which I detailed in my "Reply 1" post.

    Reply #1 = https://groups.google.com/forum/#!topic/rec.games.video.arcade.collecting/UEvunLCDm-8
    Reply #2 = http://forums.arcade-museum.com/showthread.php?t=333806

    Question #2 of 2: Is "Reply #2" correct? If yes, and that means I do not have to install a resistor (like "Reply #1" said), that's good to know, and less work overall. Regardless, the last thing I want to do is damage the PCB, so I am ready to do whatever is required to best protect it. To be honest, I really want an authentic Atari power supply, and I've been trying to find one for a while, but I've just been unsuccessful thus far.

    Thank you very much for reading, and for any help you can provide (anything is helpful: recommendations where to go to ask, other forums, etc.). I completely understand that this may be beyond the scope of the forum, so if that's the case I do apologize. Also, if this project simply won't work with this monitor I totally understand, am fine with recycling the monitor and waiting until I find something else. By the way, I started a similar thread on forum.arcadecontrols.com, but since I've received zero replies I wanted to keep looking for advice/input.

    I'll list the info detailed in the photos in case I fail to upload the photos correctly. If more info and photos are needed please let me know. Thanks again.

    Clinton Taiwan picture tube
    Matsushita Electric Industrial model #DM9010 (made Sept 198B)
    monitor yolk info = BWL779012, TLY80377T-T1, MTI MONITRONICS, TAIWAN 8839
    CHASSIS NO Y26 (not pictured; it's at the upper left of the chassis board)
    monitor came from a Brother word processor, model WP-510

    pcb.jpg chassis.jpg yolk_wiring.jpg yolk_top.jpg label1.jpg label2.jpg
    Tomek likes this.
  2. It's probably a bit beyond this forum, especially considering it's not a standard arcade monitor.

    However, I'll weigh in to say that I don't believe there is such a thing as an "authentic Atari power supply" -- my understanding is that Atari Tetris was always sold as a conversion, so it'd just be whatever power supply was available in a given cabinet rather than a model we could point to if it were released in a dedicated cabinet. Either way, my guess is that any AT/ATX or arcade power supply would probably fit the bill.
  3. Kitaru is correct; there's no such thing as a specific authentic Atari PSU. It's a regular JAMMA power supply. Just buy one of these and connect the JAMMA power pins to it - no resistor required.

    TBH it's not worth your time to get that monitor working with the game. Just pick up either a Sony PVM (the smaller ones are super cheap) and wire the RGB from the JAMMA harness to it, or try and get a hold of an arcade monitor.
  4. Kitaru and KevinDDR, thank you very much for the input and info. I do have a follow-up question for KevinDDR (or anyone else, I suppose). Won't the power supply you referenced damage the PCB? The power supply you referenced lists specs of +5V @ 15A and +12V at 2.5A, while the Tetris manual says the PCB needs +5V @ 2A and +12V @ 1A (see below snip from the Atari manual).


    Maybe my confusion is due to a lack of knowledge regarding how modern switching power supplies actually work. Does the info listed on the power supply mean that it provides "up to" 15A at +5V, and "up to" 2A at +12V? If the answer is yes, then I completely understand that any modern switching power supply will be fine for my project, whatever monitor I wind up using. If not, then I guess I need help understanding why a power supply that lists amp ratings above the manual's requirements is what I should use to run the PCB. Thanks again for your help.
  5. Muf


    Physics works such that the current drawn from point A to point B is only as much as dictated by the resistance for a given voltage (Ohm's law). Therefore, a power supply that supplies "up to 15A at 5V" will only deliver the 2A that the PCB draws from it. Voltage is defined at the output, current is defined by the resistance at the input (proportional to the voltage).
  6. Muf, I take your explanation to mean that a modern switching power supply will be what's needed for the PCB, as it will be able to provide the amps required by the PCB. Thanks very much for the reply.

    Question: so why would the Atari manual specifically call out amp requirements? Were power supplies different in 1988 and not function the way modern ones do?
  7. Because the amp requirements are still important - pretty much any electrical device from any decade will state the voltage and current required because you need to know both (unless it plugs directly into the mains). The difference is that with current the specification is a minimum rated required (unlike voltage where it's more like a maximum). If it requires a 2A power supply then a 5A supply is fine, but if you only give it a 1A supply, then at best it probably won't work and at worst you'll blow your power supply.

    As general rule, if you can't find a power supply with the exact same rating (which is obviously the preferred case):

    PSU V > Device V = Usually bad, you can seriously risk trashing your device if it's more than 10-20% higher.
    PSU V < Device V = Might not be a problem, might not allow the device to function, depends on the discrepancy
    PSU A > Device A = Ideal scenario, means your power supply won't be particularly stressed
    PSU A < Device A = Might blow the power supply, device might not work properly (often it'll work fine but occasionally will cut itself out at periods where it needs more current than it can get), or if it's a minor discrepancy it might not be a problem.

    I have no issues running a 5V, 500mA piece of equipment off a 5V, 2A adaptor. On the other hand I wouldn't run it off a 12V, 500mA adaptor because that voltage is way too high. And on a 5V, 200mA adaptor it probably wouldn't even turn on.

    Basically, match voltage. For power supply current the rating is essentially equivalent to a fuse rating - exceeding it is bad, but so long as you're under it doesn't care.
    Last edited: 14 Apr 2015
  8. Rosti, that is exactly the explanation for which I was hoping - thank you very much. Now I'll wait to hear back from TAC Rockford (I reached out to them a few days ago to ask about a schematic/manual for the Matsushita monitor), and if I'm unsuccessful and/or the monitor won't work with my project, I'll just keep my eyes out for a small Sony PVM as KevinDDR suggested. Besides, I don't have a power supply, JAMMA harness, or other control panel goodies yet - those will have to wait until I get a new job. Thank you again very much for all your help, everyone. Whenever I am able to proceed with the project I'll post again!
    Qlex likes this.
  9. I need this in some permanent form to show to people...
    Last edited: 15 Apr 2015

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