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Fire-Fli Auto Fire Circuit


Ushabin

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I stopped by the local Thrift Store this afternoon to see if they had anything I just had to have. Of course, as usual, no games or systems. I did, however, find a interesting copy of Special Projects magazine from Spring 1984. The cover touted "FIRE-FLI - Automatic Firing Circuit for your Atari!". So I snagged it and headed to the checkout.

 

Looks pretty simple (at least to me, but then again, I know very little about electronics). It's a box that plugs in between the Atari and the joystick. One toggle switch turns on the auto fire. Pressing the button on the joystick will temporarily stop the auto fire. I've attached scans of the article for anybody that might be interested to try the project.

 

Now if I could just figure out a way to have remote select and reset switches so I didn't have to keep getting up to start another game, I'd never have to leave the couch! :D

atari_fire_fli.zip

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Sounds like a neat project. Too bad I'm no good with a soldering iron.

 

Now if I could just figure out a way to have remote select and reset switches so I didn't have to keep getting up to start another game' date=' I'd never have to leave the couch! :D[/quote']

 

Simple. You just need a big long stick with a hook at the end. Or maybe two long strings with some rubber bands. Gotta love those giant toggle switches. ;)

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Funny that the designer suggests using a battery or getting power from a power supply. He doesn't even know that pin 7 of the Atari controller port is the +5v that he needs!

 

Plus this circuit is twice as complicated as it needs to be! I've built several of the asyncronous oscillator circuits that feature the 555 timer for various consoles: Atari, Vectrex, Bally Astrocade and I've fit them into a small gender box and used a cable extension for convenience.

 

Here's the ascii text diagram of the circuit that has been on the internet for some time:

 

 

2- Portable autofire

--------------------

This is a solution for those joysticks which don't have a +5V line (red

wire typically, connected to pin 7). You will need a 9-pin female and a

9-pin male connector, an LM 555 timer IC, two resistors (R1=R2=10K),

two capacitors (C=100 nF, C1=0,42 nF), a two-position switch and some

wire. Since you will need also an appropiate casing, I would recommend

you to use a 9-pin null modem adapter (e.g., Radio Shack #26-264), which

will provide you already with the casing, wiring and DB9 connectors.

 

First, build the following autofire circuit in the smallest possible

area (less than 0,5"x0,5"):

 

 


                  +5V

                  red                    firing frequency:

                   |

        /----------+                     f=1,44/[(R1+2*R2)*C]

        |          |

        Z       /--+                     ( T=0,694*(R1+2*R2)*C )

     R1 Z    .__|__|__.

        |    |  8  4  |                  

        +----7        |                  typical values:

        |    |        3----- org

        Z    | LM 555 |                  C1=0,42 nF

     R2 Z  /-6        5----             R1=10 K

        |  | |        |    |             R2=10 K

        +--+-2        |    = C1          C=100 nF

        |    |___1____|    |

        |        |         |            

        ---||---+---------/

            C    |

                blk

                GND



 

typical values:

C1=0,42 nF

R1=10 K

R2=10 K

C=100 nF

(These are the values I selected.)

 

If you are using the null modem adapter, skip this paragraph and continue

with the next. If you aren't and are building the adapter with separate

parts, then just connect each pin from the 9-pin female to the same pin

on the male connector. Now you've just built what the adapter looks like

on the inside.

 

Now, if you are using the null modem adapter: just open the casing and

accomodate the circuit inside. Make sure that all pins on the male are

connected to the same pin # on the female (i.e., pin #1 to pin #1, pin

#2 to pin #2, etc.) and not cross-connected.

 

Now for both: Connect the +5V line to pin #7 (either on the male or the

female connector, it's the same). Similarly, connect the GND line to

pin #8. Cut the wire from pin #6 just in the middle. Now, proceed to

make the following connections on the switch:

 


                    /

             A     /   B   

              o   o   o

        to    |   |   |    to

       male --/   |   -- fire

                  |

              to female



 

Now, make the appropiate holes in the casing for the switch. Fix the

switch in place and close the casing. Now the portable autofire is

ready for use.

 

Just connect the portable autofire between the joystick port on the

computer and the joystick's plug. With the switch in the A position,

you will simply bypass the autofire circuit (autofire disconnected);

when it is in the B position, the autofire is connected and the

joystick's fire button is disabled. The advantage of this design is

that you can connect the portable autofire to any joystick you want,

without having to make any permanent modification to it.

 

 

Marco Antonio Checa Funcke

Botoneros 270

Lima 33

Peru

 

reachable at jtkirk@urp.edu.pe

 

aegis.mcs.kent.edu

 

Craig Lisowski

 

clisowsk@mcs.kent.edu

 

clisowsk@mcs.kent.edu

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Along the same lines...

A couple of years ago, someone asked me for a "cheater" circuit for Decathlon. The schematic can be found at http://web.mit.edu/ecwilkso/www/VCS_hardwa...ystick_hack.jpg. Pressing up will cause you to run...you need the fire button for individual jumps and throws. The outputs can be connected to the joystick port as needed: the signals labeled "left" and "right" are always opposite from one another. Enjoy!

 

Edit: Oh yeah...the variable resistor allows you to fine tune the running speed to suit your needs.

 

-Chris

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I bought a couple of rapid fire adapters from BREgames a while back for a couple of bucks. These allow you to fire continuously without constantly pressing the fire button and I believe they were offered for the C64. Is this similar to what you saw in the catalog?

 

Pretty much. It was a box that was connected between the joystick and the Atari. One toggle switch turned it on and it would fire for you unless the fire button on the joystick itself was pressed.

 

Funny that the designer suggests using a battery or getting power from a power supply. He doesn't even know that pin 7 of the Atari controller port is the +5v that he needs!

 

I thought it sort of strange myself that he didn't just use the power off the joystick.

 

Has anybody tried putting a reset button on the joystick. I was thinking of just a momentary switch mounted on the joystick case (maybe the corner opposite of the fire button). Would running a couple of wires and attaching them to the solder points as the current reset switch work?

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Has anybody tried putting a reset button on the joystick. I was thinking of just a momentary switch mounted on the joystick case (maybe the corner opposite of the fire button). Would running a couple of wires and attaching them to the solder points as the current reset switch work?

 

Yeah, my merged Atari has a keypad which can control the 7800 pause, select, and reset signals, so it's possible. In fact you only need one wire for the reset line, because the reset switch connects it to ground and you already have ground in a joystick.

If you really wanted to get tricky, you could put a button on a joystick that connects the North and South signals to ground (through diodes so they aren't shorted to each other). Then you could put an OR chip in your console that would pull Reset low when both North and South are low. That way you could keep the standard joystick cable.

If that's not enough you could repeat the trick with another button, the Select signal, and the East and West lines. Even do it a third time with all four directions and the Color/BW signal.

Man, I may have to go build this now...:)

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Y'know, that reminds me, back in the day, I bought a rapid fire adapter. I can't for the life of me remember what it was called, but it was black plastic with gold-coloured labelling, a switch to turn rapid fire on and off, and a POT to control the rate of rapid fire. Anyone remember what this thing was?

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There is another way to build a rapid fire adapter without needing a 555 timer. Just by using a 7802 NOR gate, which is far cheaper and you'd need less compoment. As you can see in the image attached, only 2 gates are needed so you can use the second set for second button.

 

To wire it up, the input is from the joystick fire button. There is a resistor not pictured, it's a 4.7K pullup to VCC, also the VCC source for the NOR gate is pin 14. The second resistor you see is 27K and the cap is 1uF ceramic. The output is connected to the SPST switch. The center of the switch goes to the console and the other post of the switch goes to joystick fire. This is how the Sega Rapid Fire Adapter works.

 

When the switch is in one position, the fire button signal is passed through and the rapid fire is not used. When the switch is in second position, the rapid fire is enabled. If you want continuous hand free firing, you'll need to discard the pullup resistor and connect the input directly to ground.

 

Image:

rapidfire.txt

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Nice oscillator. You know, what's bizzare is that Radio Shack seems to carry 555s these days but doesn't have any basic logic gates like a 7404 or 7402 (at least my local ones don't).

We joked around in college about how anytime we had to build amplifiers in lab they would oscillate, but when we had to build oscillators they would just sit there :)

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