Hacking serial db15 (gb15) joysticks?

[IG-88]

I have a bunch of these that have been adding up over the years. Can these be successfully used as control inputs or is it worth the effort?

[boomstick]

In the past i have hacked some old generic game pads that had a DB9 (Serial type) connector that i used to use on my C-64 and megadrive with good results.  I de-soldered and removed the logic chip on the pcb, placed a few bridge wires where needed and re-asembled the pad.  Then wired up a Couple of DB9s to connect to my IPAC that the pads can plug into and hey presto.
Launch your frontend, select your chosen system and play away on the pad.

I would assume the same process could be done with some old joysticks, particularly if they use switches for their x/y axis like some old commadore sticks i had.  I dont think you'd have the same luck with an analogue stick though.

Heres a link you might find usefull:
http://dawgslair.com/joypad/joypad%20hack.html
It gave me the idea.

[BobA]

The DB15 type are usually meant for the old style PC gameport.   They are probably analog controls and do not adapt well to being made digital. Take a look inside and see if there are any pots.

[SavannahLion]

In some odd way, I miss those old DB15 sticks. Some of the best damn sticks ever made in the history of PC's came only with those DB15 connectors. There was even an old stick conversion website that sprouted up dedicated to nothing else but converting
Gameport sticks to USB.

[IG-88]

Thanks for the reply's. I grabbed a couple of the top of the pile. 1 Gravis, 1 Gravis Blackhawk and a "generic" PC propad 4. I'll assume they are analog. I will tear them apart later tonite. 

I will probably just junk them and use the USB pads I have.

Which leads me to another question, (I probably should post this under a new heading) I have never used a pc gamepad before today to play mame games. How does one remap the esc key in Mame?

SavannahLion:
Any chance of finding that site again? I tried some searching for a hour or 2 this morning on that exact subject without much luck. I know what you mean about missing using those sticks, I just don't know what to do with them...

[IG-88]

Which leads me to another question, (I probably should post this under a new heading) I have never used a pc gamepad before today to play mame games. How does one remap the esc key in Mame?

Answered my own question. I haven't used a newer version than .75 seeing as it had all the games I wanted anyway. I didn't realize that the UI changed at v.107. Now it has that esc key remap option. Nice 

[SavannahLion]

SavannahLion:
Any chance of finding that site again? I tried some searching for a hour or 2 this morning on that exact subject without much luck. I know what you mean about missing using those sticks, I just don't know what to do with them...

I doubt it. I'm not in touch with the people who frequented that site and that was an eon ago. Another forum, another life. They changed the forum software and the new search engine presentation sucks major major balls. Those ---uvulas--- don't even know how to run servers, my old website code has been exposed for god knows how long and they have no brains to at least hide it.

I'll see if I can log in again and see if I can use their ass tastic search engine front to find those original posts. I wouldn't count on it though.

[IG-88]

Well, I appreciate the effort. It's not a real big issue of course, but it would be nice to use these suckers. Perhaps I/we can figure something to do with these.....

BobA, I got busy last nite with dodging tornadoes so I didn't get to tearing them apart. I will try soon tho.

[Bluedeath]

here in Italy we say "costa pił la salsa del pesce"  (rough translation would be the topping costs more that the fish) for cass like this,  anyhow you can use a codewarrior chip or a u-hid  interface for the hack, both options aare more indicated for stratchbuilt controls rather that hacks, they costs more than a brand new PSX style usb pad (that costs around 9$). 

[IG-88]

Ya, I think I agree. Unfortunate. 

[Hornpipe2]

Yeah hacking those up should be pretty straightforward.  You can either open up your gamepad and solder directly to the traces, or make use of the interface (which is dead simple): button makes a connection from GND to (button pin).  For the sticks they're just 5V pin through 0 - 100K pots and back to individual axis pin, and you could theoretically rig stick signal through a 50k resistor by default, but left shorts around it and right adds another 50k in series.

Two joysticks can be put on one joystick port with a splitter cable (you can build yourself), giving access to 4 buttons and 4 x/y directions, or 2 X/Y and 8 buttons if you separately counted joystick 2 X as 2 inputs (left, right) and joystick 2 Y as 2 inputs (up, down) - but note that you can't hit left+right or up+down at the same time so that does limit your options to about 6.

http://www.epanorama.net/documents/joystick/pc_circuits.html

[Hornpipe2]

OOPS!  You're talking about adding a game port to your key encoder.  The buttons are easy enough - just hook pins 2, 7, 10 and 14 to separate encoder pads and then pin 4 to common encoder GND.  That leaves the joysticks, which would need a way to differentiate between ~0, ~50k and ~100k resistance and turn that into 0 or 1 button keypresses... probably requiring some fancy A-to-D conversion and a more involving circuit here than it's worth.

BUT - are you dead set on a sound card?  You could just pick one with a gamepad port on the back of it as that would do the translation work for you : )

Also, Microsoft (and maybe others) did the Sidewinder gamepad series a while back that converted button presses to digital signals over the "dumb" analog interface.  They were cool because you could daisy-chain four of them together and play over one joy port, though you needed special drivers to interpret the pulses into direction and button presses.  I have a couple in my garage, been thinking of a hack with them but it hardly seems worth it since nobody has those ports any more.  Of course that's useless now thanks to USB.

EDIT2:  Ah I like Boomstick's idea!  First you'd modify the gamepad internals to stop them from putting out analog signals and then make them put out digital directional signals (on some of the unused pins).  And then you'd add a DB15 connector to your key encoder for the extra inputs.  Of course you'd only be able to use your hacked gamepad with your improvised gamepad port but at least it's still an option, and you could do a few this way then allow your gamers their choice of pad.  15 Pins with one reserved for GND would give you 2 directions 3 buttons per pad if you wanted to rig up two...

[Bluedeath]

I forgot i on epanorama i one found (but  i don't remember the section ) a circuit that converted pc db15 to C64 (amiga etc) compatible digital joystick. it should help you