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English => Interfaces, Pinouts, Cables => Topic started by: Rekrul on May 05, 2006, 18:44

Title: Atari joystick adapter, not very sensitive?
Post by: Rekrul on May 05, 2006, 18:44
I recently built the Atari joystick to gameport adapter described here;

http://pinouts.ru/data/atari_joy2PC_pinout.shtml

I used the Radio Shack equivalents (I'm in the USA) listed on this page;

http://www.epanorama.net/circuits/radioshack_components.html

It works, however it doesn't seem to return the same range of movement as a typical analog joystick.

Perhaps it's my system. I don't have a dedicated gameport (the sound is on the motherboard, so I don't have a sound card). I use a gameport to USB adapter that I got from Radio Shack.

When I plug an analog stick into the USB adapter and go to the Windows game controller program from the control panel, the '+' is usually pretty much centered in the test window and movng the joystick will move it most of the way to the edges of the box.

When I use the adapter and plug an Atari joystick into it, the '+' is off-center to the left and up too high. Turning the 100K Ohm pots barely moves it at all. Moving the joystick only moves the '+' by a tiny amount in any direction. If I turn the pots all the way in one direction, I can get it close to centered, but then it won't move right or down at all.

I can compensate for this by using the calibration option in Windows, however I'd still like to know why it does this.

The page claims that when centered, the circuit will return a value of 50K Ohm in each direction, 0K Ohm when moved up/left and 100K Ohm when moved down/right. I don't have any software that will show the exact values, but I'd estimate that it registers about 30K Ohm when centered, maybe 20K Ohm up/left and 40K Ohm for down/right.

If I switch the USB adapater to gamepad mode, it works perfectly (since gamepads are also digital), however when it's set to joystick mode, I get the results described above. For the moment, I can make it work the way I want it to, but I'd still like to be able to make it work the way it was intended.

I don't know very much about electronics, so I'm relying on the diagram, and based on that I didn't make any mistakes that I can see.

Any advice?
Title: Atari joystick adapter, not very sensitive?
Post by: melcy on Jun 10, 2006, 15:50
im assuming you dont have an ohmeter, or a multimeter, so you cant check the actual resistance from your configuration. soldier and wire has some resistance And could be messing up your config. as stated from the design, center has to have 50k resistance on both leads to be accurate. make sure that your pots are set up correctly, you may have it backwards of linear and logarithmic. and of course, i think that your usb adapter is the main problem. this was designed to be directly to a midi/jstick port. go to an electronics store and invest $5~$10 in a multimeter with an ohms function and double check your accuracy with the pots. further help i can try with you at (slojewski [at] melcy [dot] com)
Title: Re: Atari joystick adapter, not very sensitive?
Post by: Aved on Jan 01, 2010, 03:34
Hi,

sorry for replying in old topic and maybe a bit off-topic..

i'm wondering is this kind of adapter usable for todays use (games..), or is it for use in emulators (like CCS64)?

simple question is, can the old joysticks from atari/commodore (with this kind of adapter) be used like nowadays joystics?


Thanks!
Title: Re: Atari joystick adapter, not very sensitive?
Post by: jharris1993 on Nov 07, 2010, 12:07
Aved,

Short answer:  Absolutely not!

Longer answer:
Present day "PC" joysticks are "analog", they use variable resistances to tell the computer not only that the stick has moved, but exactly how far the stick has moved, and in what direction.  (Sort of like a mouse, but upside down, with a spear in it's tummy!)

The old Atari/Commodore joysticks used switches (open/closed) to detect joystick motion.  There were four switches - up, down, left, right.

It might be possible to use them, but it's a real kludge and I don't recommend you waste your time building up an adapter when you can get a real honest-to-God analog joystick, not pull your hair out trying to solder a few dozen parts together, praying you don't smoke the parts - OR your computer - for not much more.  (depending on how fancy a joystick you want.)

IMHO, I'd just get a regular PC joystick.

Jim