Digital Controller for the Atari 5200.

[CV Gus]

Hello!

 

This is my first post in this particular area.

 

Few 5200 owners will dispute the fact that the 5200 controllers were a disaster. Who came up with the idea to use clumsy analog controllers when just about every game for it- especially arcade games- used standard digital? Games like Ms. Pac-Man, Berzerk, Qix...just awful.

 

So, being fed up, last year I set out to make a digital controller.

 

I succeeded.

 

The improvement in gameplay was fantastic. Just a short time afterwards, I beat 20,000 points in Berzerk!

 

 

If anyone is interested, then I will post a detailed text description of the project; this will include which wires do what. It will include a basic description of what the analog controller actually does. And so on.

 

I also have diagrams, but- I do not have a scanner, and I do not have access to one. Therefore, if you wish the diagrams to be posted here, then I will have to send them via regular mail to someone who can scan them.

 

`Til next time!

[iwan-iwanowitsch-goratschin]

Can we get a pic of the controller???

[midnight8]

i'm interested please post the instructs

 

Hello!

 

This is my first post in this particular area.

 

Few 5200 owners will dispute the fact that the 5200 controllers were a disaster. Who came up with the idea to use clumsy analog controllers when just about every game for it- especially arcade games- used standard digital? Games like Ms. Pac-Man, Berzerk, Qix...just awful.

 

So, being fed up, last year I set out to make a digital controller.

 

I succeeded.

 

The improvement in gameplay was fantastic. Just a short time afterwards, I beat 20,000 points in Berzerk!

 

 

If anyone is interested, then I will post a detailed text description of the project; this will include which wires do what. It will include a basic description of what the analog controller actually does. And so on.

 

I also have diagrams, but- I do not have a scanner, and I do not have access to one. Therefore, if you wish the diagrams to be posted here, then I will have to send them via regular mail to someone who can scan them.

 

`Til next time!

[CV Gus]

Here are the text instructions:

 

PART ONE: WHAT IS IT?

 

When the Atari 5200 was released in late 1982, it was an attempt by Atari to match the ColecoVision.

 

As a result, it had a good number of arcade-to-home translations, including Atari arcade games (before mid-1984, "Atari" was a single huge company).

 

Unfortunately, Atari was to make a technical decision that really ended up hurting 5200 sales: the console was released with strange controllers which did not self-center, and were "analog," not "digital."

 

"Digital" simply means on or off. When you move a regular joystick controller in a particular direction, you activate a switch that allows current to go through. This tells the game that you are doing something. When you move diagonally, you are simply activating 2 such switches at the same time. The fire buttons work the same way.

 

"Analog," however, means not only on or off, but how much. A light switch with a dimmer is a perfect example of this. With the 5200 joystick, when you moved the stick in a particular direction, the game not only knew which direction the stick was moved, but by how much. This is very clear in Missile Command- move the stick a bit to the left, and the cursor moves a bit to the left, and then stays there. Move it more, and the cursor moves more. How far the cursor moves depends on how far you move the stick over.

 

Unfortunately, there wasn't a single arcade game from that era, to my knowledge, that had such a control scheme. Most had regular joystick controls; a few had trak-balls (Centipede, Missile Command) or paddles (such as Super Breakout). As a result, it was next to impossible to react very quickly, with short, precise moves. And while it did work moderately well for Missile Command, it just wasn't as good as paddle controls for Super Breakout.

 

It was just a rotten idea.

 

 

 

 

PART TWO: HOW DOES IT WORK?

 

Using a 15-pin cable, the 5200 controller had a joystick with 4 fire buttons (2 on each side: upper and lower) and 15 buttons. These were the standard 1-9, 0, and * and #- just like on a touch-tone phone- below the joystick. The extra 3 were above the joystick and were START, PAUSE, and RESET. All but the latter 3 had different functions for different games.

 

The buttons actually were pretty standard as far as circuitry went. When you pushed the button, a small piece of conductive material would touch 2 halves of a sort of disc-shape. Each half simply connected to two particular wires, so, when you pressed a button, it was like touching the ends of 2 different wires to each other.

 

The joystick, however, was anything but standard. What the set-up actually did was to turn two different "potentiometers"- variable resistors- which are simply like two tiny paddle controllers. It was literally like having two paddle controllers: one for up and down, and one for left and right.

 

"Resistors" are things which limit the flow of electricity, just like a faucet limits the flow of water. The higher the resistance, the less flow of electricity you have. The lower the resistance, the more electricity flows. Resistance is measured in "Ohms." A 100 Ohm resistor will limit the flow of electricity twice as much as a 50 Ohm resistor.

 

A "potentiometer" is simply a resistor which can be adjusted- just like a faucet. Turn it one way, and the resistance increases; turn it the other way, and it decreases.

 

The 5200 joystick can turn both potentiometers. One controls the vertical; the other, the horizontal. The 5200 games act based on the two values.

 

In just about every 5200 game, it works like this:

 

VERTICAL= Increasing resistance moves DOWN. Decreasing resistance moves UP.

 

HORIZONTAL= Increasing resistance moves RIGHT. Decreasing resistance moves down.

 

Therefore, when you move the joystick left decreases the resistance in that potentiometer. Pull it down, and you are increasing the resistance in the other one.

 

 

The easiest way to see this is to plug in most games, and, after starting it, unplug the controller. You are completely breaking the circuit for both vertical and horizontal; this is "near infinite" resistance. Which way do you think the (whatever) on the screen will move?

 

 

If you answered "down and right," then you've got it.

 

 

 

 

PART 3: BASIC WIRING.

 

Hmmmm...now we get down to it!

 

The 5200 controller wiring is complicated only if you try to take it all in at once, looking in an actual 5200 controller. In reality, the scheme is pretty basic: with the exception of the joystick controls, everything else is simply a matter of 2 different wires touching to achieve something. That's it.

 

 

So, without further ado...here it is!

 

 

VERTICAL= RED and BLACK (with potentiometer).

HORIZONTAL= BROWN and BLACK (with potentiometer).

 

UPPER FIRE BUTTON= GREEN/WHITE and ORANGE.

LOWER FIRE BUTTON= YELLOW and ORANGE.

 

START= RED/WHITE and ORANGE/WHITE.

PAUSE= PURPLE and ORANGE/WHITE.

RESET= BLUE and ORANGE/WHITE.

 

 

Keypad Buttons:

 

1= ORANGE

2= WHITE (1, 2, and 3 touch RED/WHITE)

3= GREY

 

4= ORANGE

5= WHITE (4, 5, and 6 touch PURPLE)

6= GREY

 

7= ORANGE

8= WHITE (7, 8, and 9 touch BLUE)

9= GREY

 

*= ORANGE

0= WHITE (*, 0, and # touch GREEN)

#= GREY

 

 

In other words, touch ORANGE and GREEN and you "press" *. Touch GREY and GREEN and you "press" #. Touch WHITE and PURPLE and you "press"...if you said 5, then you have it.

 

 

Now, these colors assume you are actually using the cable from a 5200 controller. What if you don't have such? No problem, because here's where those wires lead to in a 5200 cable:

 

The 5200 controller plug has 15 holes: there are 2 rows; 8 in the top row, and 7 in the bottom row.

 

OOOOOOOO

OOOOOOO

 

I will number them. This assumes you are looking at the holes in the plug, with the 8-hole row on top:

 

01 02 03 04 05 06 07 08

09 10 11 12 13 14 15

 

01= GREEN

02= RED/WHITE

03= PURPLE

04= BLUE

05= ORANGE/WHITE

06= NOTHING

07= WHITE

08= GREY

09= ORANGE

10= GREEN/WHITE

11= YELLOW

12= NOTHING

13= RED

14= BROWN

15= BLACK

 

I also found a BLACK/WHITE wire, but it does not appear to do anything. It does not lead to any of the holes.

 

So- what if you have a 15-pin controller cable from something else? All you have to do is use a multi-tester to figure out which wire leads to which hole (if the multi-tester prong is too big to fit in the holes, just twist a bit of stiff wire to the prong).

 

If, for example, in your cable the GOLD wire leads to Hole 7, then treat it as the WHITE wire listed above. If the SILVER wire leads to Hole 12, then it is of no use; seal it off.

 

 

 

 

PART 4: THE JOYSTICK ITSELF.

 

 

This part is in conjunction with the diagrams...

 

As mentioned earlier, the 5200 joystick control is analog, not digital. In this case, the joystick actually turns two little variable resistors ("potentiometers"); one controls the vertical, the other, the horizontal. It is exactly like two tiny paddle controllers (a paddle controller IS a potentiometer).

 

As you already know, when you play Pong, Breakout, Super Breakout, Arkanoid, Canyon Bomber, or any game with a paddle controller, there is a point when the paddle (or whatever) is centered. This is because the resistance is at the point when the video game puts the object in the middle. This is important: when you release a normal joystick, it is "centered" because the game is not receiving any input from it. In the case of a 5200 joystick, the stick is "centered" only because the values of the two potentiometers are such that the game knows not to do anything (e.g. "don't move the Humanoid in Berzerk").

 

Vertical: Low Resistance=UP; High Resistance=DOWN.

 

Horizontal: Low Resistance=LEFT; High Resistance=Right.

 

When you unplug the controller, you are completely breaking the circuit. Electricity cannot flow. This is the same thing as VERY VERY VERY high resistance; that's why the game acts as if you have jammed the joystick down and to the right.

 

If there wasn't ANY resistance to these 2 currents, it would be as if you jammed the joystick up and left.

 

Therefore, the "neutral" position is between the two extremes.

 

Unfortunately, I cannot give you these values. My testing equipment is not precise enough to do it; this is why I hooked up the 2 potentiometers to my joystick set-up; I simply adjust them until they are both at the neutral value. These two potentiometers take the place of two "fixed" resistors. Just keep in mind that, once adjusted, THESE TWO POTENTIOMETERS ACT AS TWO FIXED RESISTORS THAT WOULD HAVE THE "NEUTRAL" VALUES!

 

Therefore, as long as you do nothing, the 5200 is receiving the same two values you would get if you properly centered a 5200 controller. Nothing happens.

 

What my controller does here is to alter that "neutral" value. Lessen if you want to up/left. Increase if you want to go down/right.

 

At this point, I should explain two things about connecting resistors: "Series" and "Parallel."

 

"Series" connection is when you connect two (or more) resistors end-to-end, much as you would do two batteries in a flashlight (resistors, luckily, do not have a polarity). When you do it this way, you simply add the resistances to get the total. So, connecting two 10 Ohm resistors end-to-end gives you a total resistance of 20 Ohms. Pretty much what you'd expect.

 

"Parallel" connection is when you put two resistors right next to each other and, say, twist them together, as if you were twisting two garbage ties together to get one double-strength garbage tie. If you do this with two resistors, to find the resistance you end up with use this formula:

 

(Resistor 1)X(Resistor 2)

_____________________

 

(Resistor 1)+(Resistor 2)

 

Helpful Hint: if they are of the same value, you simply cut the value in half. Two 10-Ohm resistors would become a 5 Ohm resistor.

 

So- let's take those two 10-Ohm resistors and twist them together. What do you get?

 

(10X10)/(10+10)= (100)/(20)=5!

 

 

This is the heart of my 5200 Digital Joystick. When you pull down and/or to the right, you are ADDING (in my case) 235,000 Ohms to the Neutral value(s). It is a series connection. When you push up or to the left, you are creating a parallel connection (you obviously can do this without twisting the two resistors together!), which greatly LOWERS the resistance(s). Since I use 10-Ohm resistors for this, and the neutral value is very high (thousands), you end up with a value a bit less than 10 (try the formula and see what you get).

 

There are 2 diagrams here. One shows the 2 separate circuits; the other, combined.

[Jess Ragan]

My understanding is that the neutral Ohm value for 5200 game controllers is 250K. There have been other circuits designed to convert digital controller signals to analog, and they typically use 10K, 250K, and 470K resistors. Since there ARE no 250K resistors, you need to use 100K and 150K resistors in series.

[atariksi]

My understanding is that the neutral Ohm value for 5200 game controllers is 250K. There have been other circuits designed to convert digital controller signals to analog, and they typically use 10K, 250K, and 470K resistors. Since there ARE no 250K resistors, you need to use 100K and 150K resistors in series.

 

And don't forget some people prefer using diodes instead of resistors to get the near zero resistance as in this adapter here:

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...em=320205656680

 

Games like Pac-man seem to require that you get the zero pot reading to move in two of the four directions. I guess the programs are looking for these near zero values when reading the POKEY chip.

[Shawn]

My understanding is that the neutral Ohm value for 5200 game controllers is 250K. There have been other circuits designed to convert digital controller signals to analog, and they typically use 10K, 250K, and 470K resistors. Since there ARE no 250K resistors, you need to use 100K and 150K resistors in series.

 

And don't forget some people prefer using diodes instead of resistors to get the near zero resistance as in this adapter here:

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...em=320205656680

 

Games like Pac-man seem to require that you get the zero pot reading to move in two of the four directions. I guess the programs are looking for these near zero values when reading the POKEY chip.

 

 

Where you not told like a year ago to stop spaming threads with auction links to your damn silly wire?

[atariksi]

My understanding is that the neutral Ohm value for 5200 game controllers is 250K. There have been other circuits designed to convert digital controller signals to analog, and they typically use 10K, 250K, and 470K resistors. Since there ARE no 250K resistors, you need to use 100K and 150K resistors in series.

 

And don't forget some people prefer using diodes instead of resistors to get the near zero resistance as in this adapter here:

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...em=320205656680

 

Games like Pac-man seem to require that you get the zero pot reading to move in two of the four directions. I guess the programs are looking for these near zero values when reading the POKEY chip.

 

 

Where you not told like a year ago to stop spaming threads with auction links to your damn silly wire?

 

Some people just can't see REALITY. I answered that before and now I'll give you more... Do you consider shareware spamming as well? You should if you consider this spamming. I don't even think you even read what I wrote previously given you biased state of mind. Shareware has a potential of making money but it is being made available for use at almost zero price. This adapter costs more to make than it is being sold for. It has a potential of making money if the final price goes over what it cost to make the adapter. Got it? Or should I spell it even further details? I am trying to show there's something unique not trying to spam advertisements. I have many other products which I never gave a link to here.

 

You want to get me thrown out-- go start a campaign and complain you may just get some biased people on your side.

[thursday83]

I think you should build one and sell it to me. I would like a digital controller or 4 for the 5200.

[BigO]

This is the heart of my 5200 Digital Joystick. When you pull down and/or to the right, you are ADDING (in my case) 235,000 Ohms to the Neutral value(s). It is a series connection.

I tinker with controllers some and I'm curious about your implementation of this. Any pictures?

It sounds like you may have done this with all passive electronics. Did you use a double throw switch to implement the increased (serial) resistance? Or do you have active electronics?

 

If you still need someone to scan the documents, PM me.

Edited January 24, 2008 by BigO

[Prodos8]

The Coin Controls Comp Pro sticks don't use any 'active' components, just switches and resistors. The good thing about that is you can use a normal 5200 controller cord since it isn't wired to the +5v you need for ICs/transistors. I worked out a diagram to convert one of those Radica Space Invaders sticks over to the 5200 but haven't gotten around to it yet.

 

I actually prefer the adapters since you can then choose from many different controller options.

 

@CV Gus I'd also like to see pics/schematics for your controller.

[PacManPlus]

You mean like this one? http://www.atariage.com/forums/index.php?s...4&hl=Radica

[Prodos8]

You mean like this one? http://www.atariage.com/forums/index.php?s...4&hl=Radica

Yup, that's the one! I was too busy making a RSI-7800 stick back then and besides I didn't have a 5200 at the time.

[BigO]

The Coin Controls Comp Pro sticks don't use any 'active' components, just switches and resistors. The good thing about that is you can use a normal 5200 controller cord since it isn't wired to the +5v you need for ICs/transistors. I worked out a diagram to convert one of those Radica Space Invaders sticks over to the 5200 but haven't gotten around to it yet.

 

I actually prefer the adapters since you can then choose from many different controller options.

 

@CV Gus I'd also like to see pics/schematics for your controller.

 

I've assumed that such digital adapters require either double throw switches or active electronics. I haven't seen any evidence to the contrary. I'll have to take a look at your scheme for the SI stick when/if you make it available.

 

I have something I want to try that I imagine will work with passive components and ordinary single throw switches. I keep expecting to hear someone say they've done it or at least tried and failed. I waste enough time on this stuff as it is without reinventing the wheel...

 

Though it makes sense, I wasn't yet aware that the 5v wasn't pinned through a standard controller cable. I've messed with trackballs and my custom stuff so much that I have barely touched the stock controllers. Glad that came up now.

Edited January 24, 2008 by BigO

[Prodos8]

I've assumed that such digital adapters require either double throw switches or active electronics. I haven't seen any evidence to the contrary. I'll have to take a look at your scheme for the SI stick when/if you make it available.

 

I have something I want to try that I imagine will work with passive components and ordinary single throw switches. I keep expecting to hear someone say they've done it or at least tried and failed. I waste enough time on this stuff as it is without reinventing the wheel...

Well the pic I posted above pretty much is the schematic for it. Its not an adapter its just showing how I'd planned to rewire the stick to work with the 5200. In order to make an adapter I think you're pretty much stuck with using a circuit with ICs/transistors.

 

The simplest scheme for custom building a stick, that I could come up with anyway, would use two single throw switches for each axis. One would need to be N.O and the other N.C. Maximum resistance would be an open circuit, though I've read some games don't like that, but should work with nearly all of them.

[CV Gus]

I do have the plans (diagrams) for my version drawn up; I just do not have a scanner, or access to one. Therefore, I'd have to mail off copies to someone who does, so he can put them up here. But so far, nobody has ever expressed any interest in doing so.

[Tom_Explodes]

If you still need someone to scan the documents, PM me.

 

Actually, BigO did. See?

[BigO]

I've assumed that such digital adapters require either double throw switches or active electronics. I haven't seen any evidence to the contrary. I'll have to take a look at your scheme for the SI stick when/if you make it available.

 

I have something I want to try that I imagine will work with passive components and ordinary single throw switches. I keep expecting to hear someone say they've done it or at least tried and failed. I waste enough time on this stuff as it is without reinventing the wheel...

Well the pic I posted above pretty much is the schematic for it. Its not an adapter its just showing how I'd planned to rewire the stick to work with the 5200. In order to make an adapter I think you're pretty much stuck with using a circuit with ICs/transistors.

 

The simplest scheme for custom building a stick, that I could come up with anyway, would use two single throw switches for each axis. One would need to be N.O and the other N.C. Maximum resistance would be an open circuit, though I've read some games don't like that, but should work with nearly all of them.

 

Somebody was just asking me a question on this subject so I came back to have a look at your first picture using the double throw switches. In reading this later post, I have a potential solution for the potential problem that you mentioned.

 

If some games don't like the infinite resistance that would occur when you open the NC switch, I think you could just put another 250K resistor across the terminals of the NC switch so that the resistance goes up to around 500K instead of "wide open".

[CV Gus]

Help on 5200

I'm trying to make a Arcade Style Atari 5200 Controller, but don't know how to convert the digital signal of microswitches to analog. Can you help me?

 

Fred

 

Manaus - Amazonas - Brazil

********************************

 

Hello!

 

First, I'm sorry for the delay- I do not have a computer myself, and so must use the ones at the library. At this time of year, it may be several weeks before I can do this (the winters up here are TERRIBLE).

 

From your question, I assume that you are trying to build a controller yourself.

 

The one thing you have to keep in mind is that when you move the stick on a 5200, you are turning little "potentiometers"- variable resistors. This increases or decreases the resistance of them.

 

Look at it like this- do you remember the paddle controllers for the old Atari VCS (2600)? remember how they were a pair you'd plug into one controller jack?

 

Now, think of Breakout. You'd turn the controller to move the paddle left and right. Now, imagine if by turning the OTHER controller, you could move it up and down, too.

 

That is EXACTLY how a 5200 controller works.

 

When you turn the paddle, you are changing the resistance in the potentiometer in the controller- that's all that it is. As the resistance changes, the paddle moves to a different place.

 

Now, think of that paddle all the way to the left, all the way to the right, and in the very middle. If you made a controller with 3 buttons, each one a FIXED resistor with the correct value, you'd get the paddle to go to those 3 places by pushing those buttons.

 

That's the heart of my controller design- if you read the text of my controller post, you'll notice that what I did was to design a controller that does something like the above.

 

The 5200 potentiometers I use in my design you adjust until you get a "neutral" value- I use Missile Command. I adjust both potentiometers until the crosshairs (the +) is smack-dab in the center of the screen. When you've done this, the resistances in BOTH circuits are exactly what they'd be in a regular 5200 controller if the stick is centered.

 

Now, what my joystick does is, when you want to move UP or LEFT, a fixed resistor is added in a "parallel" set-up. This DECREASES the resistance in the circuit, which moves you up or down.

 

What gave me trouble was the DOWN and RIGHT. The only way to do this was with a button that works opposite of a normal one- this actually COMPLETES the circuit when you are NOT pressing it! (It's called a "Normally CLOSED" switch).

 

When you pull DOWN or to the RIGHT, my joystick presses down on these buttons. The regular circuit is broken, forcing the current to go through a fixed resistor with a high resistance (in my prototype, 235,000 OHMS).

 

That's the trick I use- those peculiar buttons.

 

I am going to respond to that person who has offered to post my plans right now- soon, you will be able to see them, and that will explain it all clearly.

 

Good luck!

Edited March 6, 2008 by CV Gus

[Prodos8]

Somebody was just asking me a question on this subject so I came back to have a look at your first picture using the double throw switches. In reading this later post, I have a potential solution for the potential problem that you mentioned.

 

If some games don't like the infinite resistance that would occur when you open the NC switch, I think you could just put another 250K resistor across the terminals of the NC switch so that the resistance goes up to around 500K instead of "wide open".

Good idea! Yep I think that would work fine and eliminate the open circuit condition.

[CV Gus]

First, my apologies- above I said 435,000 Ohms; it should be 235,000 Ohms.

 

Second, good news- I am sending out the plans today! Thanks to Big O, they will soon be here!

 

One of them is a very simple plan, using only a few simple parts: a bit of wire, a 235,000 Ohm (or even a 200,000 Ohm) resistor, a 10 Ohm resistor, and a variable resitor, if not from a 5200 controller, then one of, say, 500,000 Ohms.

 

Since I do not know when I will next be here, I will give the text explanation in advance...

 

In this set-up, you are using the BROWN and BLACK wires from the 5200 controller. This controls the HORIZONTAL movement. Thus, Missile Command or Super Breakout can be used as test cartridges.

 

 

Keep in mind the following:

 

1) Electricity flows from negative to positive and,

 

2) Electricity always chooses the path of least restance. If you split a wire in two, connect a 100 Ohm resistor to one of them but nothing to the other, and then join the two wires together again, the current will not flow across the resistor; it will go across the other wire.

 

 

******************************

 

Upon setting this up...

 

First, adjust the variable resistor until the paddle or crosshairs is centered horizontally. This is your NEUTRAL value, as if the joystick was centered. The current goes from the black wire through the twisted-together wire (simulating the "NORMALLY CLOSED" button) and through the variable resistor (path "A").

 

To simulate pushing LEFT, touch the ends of that broken wire together. This creates a "parallel resistor" set-up with the variable resistor and the 10 Ohm resistor- the result being a much, much lower resistance (as explained above). It would be close to 10 Ohms.

Be sure to disconnect them again when you are done "pushing left."

 

To simulate pushing RIGHT, disconnect the twisted-together wire. This simulates pushing down on the NORMALLY CLOSED button, which breaks the current. The only way the current can flow now is to go through the 235,000 (or 200,000) Ohm resistor (path "C"), IN ADDITION to the variable resistor (a "series resistor" set-up). This boosts the overall resistance in the circuit.

 

That's all there is to it! The tricky part is actually building or modifying a joystick...

 

Time's up for today. Good luck!

Edited March 6, 2008 by CV Gus

[BigO]

Keep in mind the following:

 

1) Electricity flows from negative to positive and,

Another electron flow guy...

[CV Gus]

In my prototype, I used 10 Ohm and 235,000 Ohm resistors.

 

I noticed something about a previous effort: in that one, to get the super-high resistance (for right and/or down) I merely broke the circuit altogether (near-infinite resistance).

 

However, this resulted in a number of cartridges being unplayable.

 

It wasn't until I lowered the resistance using the 235,000 Ohm ones that this was mostly solved.

 

I say "mostly" because my digital joystick is not 100% quirk-free.

 

In Ms. Pac-Man, for example, when you start the very first game, you must tap the joystick to the left. You only have to do this once; after that, as long as the cartridge is being played, you're fine.

 

In Kangaroo, you must tap the joystick left and then down at the very beginning; as with Ms. Pac-Man, that'll do it for the rest of the game time.

 

Sometimes in Defender, you must tap down. Again, just that once.

 

There are a number of games which do not have this minor problem: Berzerk, Pac-Man (oddly enough), Qix, Robotron: 2084, and others.

 

Due to the problems I encountered the first time, My guess is that the resistnaces are not quite right; for my next effort, I will use 200,000 and 100 Ohm resistors to replace the 235,000 and 10 Ohm resistors.

 

Also keep in mind that this is a digital joystick. You cannot play Missile Command or Super Breakout with it. Some games, like Star Raiders, Centipede, and Pole Position, will be a bit awkward, since the regular 5200 joystick allowed some subtleties you cannot get from a digital joystick.

 

But that aside, even with its quirks, it's good. My scores in a number of games, especially Berzerk, are improved- I broke 20,000 points with it!

 

But all in all, it was certainly worth the effort. Back in happier times, I used to enjoy games like Berzerk, Qix, Defender, Pengo, etc. When I found that Atari 5200, along with a number of games and instruction booklets(!) at that 1998 townwide garage sale, I purchased it. Unfortunately, it was broken: the plug for controller #1 was not intact. It took some effort moving one of the other jacks to that one, but it was satisfying enough at the end. To have heard "Chicken! Fight like a robot!" for the first time in years was terrific.

 

It was a good system. But why did Atari not come out with digital controllers immediately? If I could build one, then what stopped them from what was an obviously necessary project?

 

 

Edited March 6, 2008 by CV Gus

[BigO]

Got the documents. Will try to remember to take them to work Monday and scan them.

[BigO]

Here's the aforementioned documentation from CV Gus.

There's one more piece, a Polaroid(!) of the finished setup, but I'm having a tough time getting a clean scan of the sepia toned photograph (mostly because I'm using equipment at work and don't want to stand there too long )

Edited March 11, 2008 by BigO