Voltage from parallel port

[cbmeeks]

Ok, I am an eletronics newbie here.

On my cab, I am going to allow NES games to be played as well as MAME.  I thought it would be uber cool to put two NES ports in front of my CP.

So, I bought some NES extension cables (so I wouldn't have to hack my NES controllers) and I got myself a multimeter last night.

I have never used a multimeter before and I know very little about electricity.

I have read that mose parallel ports can't really give the 5 volts needed for the NES controller...and I want two of them.

I plugged a cable into the DB25 port of the computer (parallel) tested:

Pin 6 (power) to Red (positive) cable of the multimeter
Pin 18 (ground) to the Black (ground) cable of the multimeter

The multimeter showed 3.18 (which I assume is volts).

Here are my questions:

1) Is this correct?  Is my parallel port not giving the full 5 volts?

2) Can I get hurt from the parallel port?  In other words, is there enough juice to cook me?  lol

My plans actually call for getting the 5 volts from the PSU....mainly because I might have 2 NES and 2 Atari controller support so I know the PSU should be enough.

3) How dangerous is mucking around with the PSU?  Now, I am smart enough not to lick the cables while the thing is plugged up (or unplugged) but what I am wondering is if I accidently touch the cables while powered on or if there is some current hanging around after being unplugged is it going to zap me good.

Thanks!

cb

[mattv]

3) How dangerous is mucking around with the PSU?  Now, I am smart enough not to lick the cables while the thing is plugged up (or unplugged) but what I am wondering is if I accidently touch the cables while powered on or if there is some current hanging around after being unplugged is it going to zap me good

I suspect this will be the last post we see from cbmeeks :-)

3) How dangerous is mucking around with the PSU?

This can be very dangerous especially coupled with the fact that you know very little about electricity. In fact I would go so far as to say that this is a recipe for disaster.

[cbmeeks]

Awww, come on...give me a little credit.

I am pretty good at wiring networking and telephone equipment.  :-P

cb

[DaveMMR]

Ever see one of those bumper stickers that says "Wiring's no hobby: call an electrician" or something to that effect.  Well heed that advice because mucking around inside a PSU is something you do not want to do unless you absolutely know what you're doing.  'ZZZZappp!'

[krick]

In order to get any appreciable voltage from a parallel port, you have to tie multiple pins together using diodes.

I built an SNES to Parallel port adapter way back in the day and this is the technique they recommended.

There were several projects like this...

SNESPro
Direct Pad Pro
SNESKey

You can find all about them and more here...  
http://snespad.emulationworld.com/


Remember, you need to to more than just hook a controller to a parallel port.  There needs to be some sort of drivers installed to allow windows to see the device and either translate the input into keyboard presses, or interface into the DirectInput API.

That parallel port business is a lot of work, you might want to have a look at this instead...
Classic controllers converted to USB for use on your computer:
http://www.sealiecomputing.com/retrozone/

[IncrdblHulk7]

I have completed a similar setup - which I plan on incorporating into my CAB (when I get around to building it).

I followed the plans for the JUMP interface:
http://www.dreamcliff.com/personal/daniel/jump/

I chopped off the connectors to a bunch of SNES and NES controllers and attached DB9 connectors to the ends.  That way I can plug in SNES or NES into same port (requires some driver manipulation).  The parallel port can support enough power for SNES pads - but not for power hungry NES pads.  Therefore you need to supply a better power source than Parallel Port.  They go over a couple options on the JUMP page.  I simply took a PS adapter from an old fan and use that to connect the PSU's 5V and GND in place of the Power pins from Parallel port.

Hope this helps.

 

[StephenH]

You may want to use +5V from an unused Disk Drive connector and route it to one of the pins.

[cbmeeks]

Remember, you need to to more than just hook a controller to a parallel port.  There needs to be some sort of drivers installed to allow windows to see the device and either translate the input into keyboard presses, or interface into the DirectInput API.

Yeah, I know.  I use NTPad and I am a programmer so I could probably write other drivers if needed.

That parallel port business is a lot of work, you might want to have a look at this instead...
Classic controllers converted to USB for use on your computer:

There is a reason why I didn't want to use the USB versions of the controllers.   That USB NES controller is like $25.00.  I can buy an NES controller for $2.00.  I wanted to be able to have two players ($5.00 instead of $50) and I wanted to easily replace the NES controller if needed.

I am just going to use the 5V and ground from my PSU.  I have already soldered some extension wires from a molex connector so I think that should work out well.

Thanks guys

cb

[MisterB]

I've built several parallel port controller interfaces for my cab.  As mentioned earlier, attaching diodes from the data line pins to the NES +5 should give you all the power you need.

My preferred driver software is PPJoy, which supports numerous interfaces.  You can also find interface schematics for all the supported interfaces on it's website.