CX40 joystick PCB pinouts

[+Philsan]

Which cable colors are pin 1 (joy up), 7 (+5v) and 8 (GND)?

Thanks!

 

[+Nezgar]

[Deleted incorrect useless info]

[Rybags]

As per most standards, Black is GND (note how it snakes around to every button connection)

Switch activation means the direction/fire is connected to GND which overcomes the weak pullup bringing it to 0 rather than 1.

 

Orange woud be the TRIG input.

[+Philsan]

As per most standards, Black is GND (note how it snakes around to every button connection)

Switch activation means the direction/fire is connected to GND which overcomes the weak pullup bringing it to 0 rather than 1.

 

Orange woud be the TRIG input.

Thanks.

GND = BLK

UP = ?

+5v = ?

[+mytek]

Thanks.

GND = BLK

UP = ?

+5v = ?

I'm guessing WHT = UP and BLU = DOWN. There is no +5v available on the cable, because it is not needed for a joystick.

[+Philsan]

Thank you.

 

I have to connect to Atari this DCF77 radio time receiver

 

I tought to use a CX40 joystick cable but if it doesn't have pin 7 (+5V) I was wrong.

 

Other no soldering solutions?

 

 

[+mytek]

Cool idea .

Unfortunately since the joystick cable has an encapsulated (molded rubber) joystick connector there is no 'pretty' way to modify it to allow rewiring one of the unneeded wires to pin 7. However if the current requirements are low (which appears to be the case), it might be possible to get what you need from the unused LEFT or RIGHT switch inputs via the A8's internal pull-up resistors. And for a bit more drive current, parallel connect those to the DCF-77's power input. Although judging by the interface circuit you showed, it appears that the pull-up resistor of one joystick input might be all that's required.

 

Edit: Apparently there are no pull-up resistors being used externally on the 6520 PIA in the A8. The application relies on the inherent weak pull-up of the TTL inputs. So I'm not sure if this will work, but if it stands a chance at all, you would need to parallel up as many of those unused inputs as needed to create enough drive current (minimum of 1.2V) to run the DCF-77, which would probably not be enough to run the LED power indicator, so that should be left off of the circuit. I drew up an example of what I am describing...

 

 

The inline 1K resistor was eliminated, because we don't need the current limiting it was originally intended for to drive into the LED, which was also being used like a zener diode to limit the voltage to 1.2V. A TTL input's weak pull-up will not exceed the maximum power supply for the DCF-77.

[_The Doctor__]

I'm sorry but what the issue with getting pin 7? standard 9 pin connectors... solder up the wires... , also depending on controller, it may have all wires but are snipped off flush with the end. Investigate what's in a paddle controller as well.

 

Last thing of note is Every joystick/paddle extension cable I have ever bought has ALL of the pins wired and connected straight through...

Edited August 24, 2018 by _The Doctor__

[+mytek]

I'm sorry but what the issue with getting pin 7? standard 9 pin connectors... solder up the wires... , also depending on controller, it may have all wires but are snipped off flush with the end. Investigate what's in a paddle controller as well.

 

Last thing of note is Every joystick/paddle extension cable I have ever bought has ALL of the pins wired and connected straight through...

 

The OP obviously wants to re-purpose an existing joystick cable which I presumed did not have a +5v (pin 7) connection. Now you got me curious, so I'll take a peek at some of mine and see if those extra connections are present, but not in use. I can definitely see where a paddle controller would have it, since it's needed for the pots.

[ivop]

Note that _The Doctor__ said extension cable. I almost fell in that trap myself Joystick cables themselves definitely don't always have all pins connected. When we were building multijoy8 boards in Maarssen, we had to cannibalize quite some throwaway joysticks to have enough cables that were 9-9 all-through.

 

Edit: a lot of joystick cables had only up/down/left/right/trig/gnd.

Edited August 24, 2018 by ivop

[Brentarian]

A Sega Genesis extension cable should work as I believe the gamepads use all 9 pins.

[+mytek]

Just for grins I tested out my theory on stealing power from all of the unused joystick inputs, and I'm happy to say it appears to work with the original interface circuitry. And as suspected, the more unused inputs in parallel, the more current is available.

 

Here's an updated modified schematic...

 

Turns out that both a RED and a GREEN LED I had laying around dropped the voltage down to +3v from the source, and 1.2V at the LED. Without the LED in circuit, the inputs rest at +5v which was higher then I thought they would be. I think it's good to keep the 1K resistor/LED in circuit to act as overvoltage protection for the DCF-77 module, especially if the inputs got turned into outputs when the module was still connected (not required, see edit). Since a 1K resistor current limits to 5 ma at +5v, I'm assuming that the DCF-77 module has very low current requirements (3 ma).

 

A good article on DCF-77: https://blog.blinkenlight.net/experiments/dcf77/dcf77-receiver-modules/

 

Edit: I located the spec on the power supply requirements HERE, and it appears to be 3 ma with a voltage range of 2.5-15v. So the 1K resistor/LED would not be required, and could be left out, thus yielding a bit more current if it proves insufficient for the DCF-77 module with the LED in use.

 

Edit2: Since the spec on the Conrad site calls out a minimum of 2.5v, I made some additional modifications to the schematic to better accommodate that, while still retaining the LED if desired.

[Mathy]

Hello Philsan

 

Since you are probably going to use some kind of case for this, why not use a small piece of ribbon cable between a crimp on DB9 connector and the PCB? You will not see it later on and when you mount the DB9 connector to the case, the ribbon cable will not be mechanically stressed. The joystick extension cable you'd need to connect between the case and the Atari can also be used for other purposes when the DCF-77 receiver is not used. But the biggest advantage is that you do not have yet another device with a cable hanging from it when not in use.

 

Sincerely

 

Mathy

[Rybags]

BRN = right

WHT = up

BLK = GND

BLU = down

GRN = left

ORG = fire

 

As stated there's no +5V on a standard joystick. Though some other controllers will have what you need. Paddles yes but you don't really want 2 cables into 1 and they're a rarer controller type. Atari keyboard but same with rarity.

Possibly a Sega type pad or a joystick that has autofire would supply the +5V as well as GND.

 

Interesting idea to use unallocated stick inputs for current - in theory you should also be able use the TRIG input in the same way.

Voltage drop from the LED - wouldn't that be potentially variable depending on what era the LED was made?

[+mytek]

BRN = right

WHT = up

BLK = GND

BLU = down

GRN = left

ORG = fire

 

As stated there's no +5V on a standard joystick. Though some other controllers will have what you need. Paddles yes but you don't really want 2 cables into 1 and they're a rarer controller type. Atari keyboard but same with rarity.

Possibly a Sega type pad or a joystick that has autofire would supply the +5V as well as GND.

 

Interesting idea to use unallocated stick inputs for current - in theory you should also be able use the TRIG input in the same way.

Voltage drop from the LED - wouldn't that be potentially variable depending on what era the LED was made?

 

Thanks for the confirmation on the colors vs. the assignment .

 

Yes I did end up using the fire button input as well. When I was testing the idea, each input added in parallel increased the voltage seen while under load, including the fire button.

 

Yes the voltage drop will vary slightly for what color, and what efficiency LED is used, but generally it'll be pretty close to 1.2v for red, green, or yellow. a blue LED would likely be much higher.

[+Philsan]

Thank you guys!

 

Just for grins I tested out my theory on stealing power from all of the unused joystick inputs, and I'm happy to say it appears to work with the original interface circuitry. And as suspected, the more unused inputs in parallel, the more current is available.

 

Here's an updated modified schematic...

Atari-2-DCF_interface.png

 

 

 

Do you think this would work?

 

[+mytek]

It appears that the present version of the Conrad DCF Receiver has changed from what was originally shown on Ralf Zimmermann's schematic. Apparently the receiver module has two open collector outputs built-in, so no need for an external NPN transistor. Based on the current information shown HERE, I would think the connections would be more like this.

 

 

 

At least that's how I interpret it. But the diagram could be inverted from reality.

[AtariGeezer]

Found a cheap receiver on ebay.

eBay Auction -- Item Number: 262551885004

[+Philsan]

Thank you very much Michael! Thanks Jay too, I think the receiver you found is cheaper because Conrad add a fee for small orders.

 

The goal is to use the attached A8 program (found by CharlieChaplin), but for tests I am using an Atari ST program:

https://ralfzimmermann.de/dcf_time/index.html

 

With an old receiver (with leds) I get some informations (receiving, decoding, disturbed signal).

 

Unfortunately with Conrad's receiver nothing happens.

Perhaps faulty joystick cable, faulty receiver, faulty user (likely...).

 

I have this joystick extender I could use instead of the old Atari CX40 cable:

 

But how will I distinguish the cables?

Are they colored like Atari CX40 cable?

 

 

DCF-77_Funkuhr.ATR

[ivop]

Never trust colors. Measure which pin connects to which wire. Seriously, there is no color standard for such cables.

[Mathy]

Hello Philsan

 

As I said, use a crimp on DB9 connector and a short piece of ribbon cable. No need to cut up cable, no need for soldering, no need to not be colorblind, no need to measure which pin/wire goes where.

 

Sincerely

 

Mathy

[+Philsan]

Hello Philsan

 

As I said, use a crimp on DB9 connector and a short piece of ribbon cable. No need to cut up cable, no need for soldering, no need to not be colorblind, no need to measure which pin/wire goes where.

 

Sincerely

 

Mathy

Thank you Mathy.

I think you mean those (female).

The only problem is I don't have them and they are available from China (in Europe they seem expensive).

[Mathy]

Hello Philsan

 

Yes, those are the ones. The blue connectors.

 

Sincerely

 

Mathy

[+Philsan]

Find DB9 crimp connector and cables in Europe, assembled, but no luck.

 

 

On the other end, after many attempts, the Atari ST program read the time from my Düsseldorfer Ei Atom-Uhr.

That device has a led, so it's easier to see if there's the signal.

Unfortunately where I live the signal is very weak so doing tests is a nightmare.

The A8 program attached in post #19 didn't work.

That Basic program (with an assembly routine) doesn't show any feedback.