Get rid of Adapter Lags

[-Scorpion-]

Hi,
I built two Homepads for myself and tried several Input Devices. I soon found out that using an PSX Pad + PSX to USB Adapter is definitely the worst solution. But these things are used by most players.
So I thought of a way to improve the feeling to make it more like the Arcade. Everyone of you who play at the Arcade and SM at home should know the huge difference.

Hint: I'm using AC timings, not the Default ones. If you use the default timings, chances are high that they "eat up" the lag since they are so damn big


Let me tell you sth about USB clock first:

USB's default clock is at 125HZ, which means that the status of USB devices is updated every 8ms. Doesn't sound too much, but this is not the only Lag. Other Lag sources are the device itself and the PC.
There is a Tool available for Win XP and Win 2K users (sry, no Win98/WinME) which can increase USB clock up to 1000HZ (1ms). The Tool's Author warns about 1000HZ because it could damage your hardware, but 500HZ(2ms) should be a safe setting.

Hint:
USB should be normally capable of handling up to 1000HZ, some of the Razor mice enable it automatically in Win 2K. But in Win XP it does not work at all, USB clock stays at 125HZ.


This is the tool:
http://www.majorgeeks.com/download4469.html

With this you can test if the Patch succeeded:
http://dev.terrorfaction.com/dx_mouse_timer_dialog.zip
http://tscherwitschke.de/download/mouserate.zip


This link describes what the tool does. It's interesting,
but I prefer to let the tool do the work ^^
http://www.warleagues.com/viewnews.asp?view=45&page=2



Now about the Input Device itself:

The Problem is that you can't just use any Device and solder it onto your Pad, they have to withstand the static charges caused by playing with shoes on Plexiglas. I don't have this problem cuz my Pads are made of wood, but commercial Pads do have it.

I tried the following Devices:

- PS2 Keyboard
Amegon used this Device, but it felt strange somehow. After some time we found out that the PS2 Port ist clocked at 40Hz or sth like that, meaning that its status is updated every 25ms. This is definetely far too slow for Stepmania!


PSX Adapter:
-clumsy feeling, worse than everything except PS2 Keyboard. I'm not talking about Offset, I mean something like a huge erratic Lag just like the PS2 Keyboard has.

USB Gamepad:
-Is much better than an Adapter, but you have to solder directly onto its buttons (difficult for unexperienced people) and it doesn't resist Static charges. Everytime I played with shoes the Pad didn't react after a few minutes. Replugging helped, at least the gamepad wasn't totally damaged.


- Xbox Controlbox for TX2000+ Metalpad
Xbox uses the USB Standard, so the only thing you have to do is to solder an USB connector onto it and download the drivers!
Well, this one is able to withstand the static charge cuz it's made especially for Metalpads.
I had one of my homepads connected to an USB Gamepad and the other one to an Xbox controlbox. I found out that both Pads reacted different, you had to step earlier with the USB Gamepad. So this one is even better than an USB Gamepad.
I think that this one should also be the best choice cuz it's made especially for DDR, meaning that it should be optimized to reduce Lag.
Xbox controlboxes should be available for all Metalpads out there. This should also work with Xbox Softmats.


Here's a short Howto:

You'll need an USB cable and soldering stuff. Soldering skills are recommended, but the soldering part isn't difficult at all.
Open the controlbox and solder the wires where the other wires of the xbox cable are. The colours of both cables should match, unless you use the TX2000+ Controlbox. They exchanged green with white. I don't know exactly about other controlboxes.


This is the pin assignment for homepad builders or other purposes:

http://xs.to/xs.php?h=xs24&d=05152&f=Xboxpad.JPG

1: ???
2:Button: Up
3:Button: O
4:Common/Ground for Buttons
5:Button: X
6:LED- (?)
7:LED + (?)
8:Button: Right
9:Button: Left
10:Button:Down

This is the driver:
http://redcl0ud.hostrocket.com/files/XBCD_DDR.cab

This one is especially made for DDR and maps the Pad's buttons not to axes, you don't have to change any settings or do some sort of combination to get it working.
To get the Xbox CB recognised by the driver, add this line in XBCDddr.inf, submenu [DeviceList]:
"XBCD XBox DDR Pad"=Install, USB\VID_FFFF&PID_FFFF ; Xbox Controlbox


This is it!


I tried to prove my suppositions: I used the LPT Lights Driver for RC2 and connected it with the input device via Transistor and then made a comparison between the S-Joy USB Adapter and the TX2000+ Controlbox. The difference is incredible huge:
The controlbox had an erratic Lag of 8ms and the Adapter had 23ms. Since the driver itself could be a source of lag that doesn't exist while stepping, the test's result is questionable. The Xbox CB has to maintain this Lag, too, but it has only 8ms Lag. So the Adapter has an erratic Lag of at least 15ms, which is too much.
I also found out that the approximate offset difference between Xbox CB and Adapter is around 15ms, meaning that the Adapter sends its signals about 15ms later than the Xbox CB.

After having played with the Xbox CB for a while I borrowed a PSX CB with Adapter and tested it. After 5 minutes I put it away because the feeling was totally different, it was definetely worse. It felt clumse and I was even able to see the Lag with my eyes, my Scores were crappy.

I don't want to explain the detailed test procedure since I already did that in a German Forum. If you are able to understand German, go ahead and read this thread:
http://www.vierpfeile.de/vp/modules.php?name=Forums&file=viewtopic&t=2465&postdays=0&postorder=asc&start=60

I think it's not too important to see the exact difference, it's rather more important that the Xbox Controlbox is way better. Since Xbox CBs are very cheap, just try them!
I'm positive that you will notice the amazing difference immediately and not regret it


Sry for my mistakes, English isn't my native language. If you don't understand something, feel free to ask and I'll try to explain


-Scorpion-

[Cutriss]

Huh. I only skimmed this article, but I hadn't ever thought of the idea of forcing the sampling rate on the adapter to make it run faster to reduce the latency. That's a pretty good idea.
_________________

Sentient Mode is capable...

[shocker]

wow, very nice info there.
i can't stand playing stepmania with my ps2 to usb adapter because of the lag (i use the parallel port adapter instead, so i can only play single player ). are you saying that changing the USB default clock to 500mhz using that tool will fix it?

[-Scorpion-]

Nope, I'm not saying that the Patch will fix the whole Problem.


As I already have written, USB itself has 8ms erratic Lag, while the PS2 to USB Adapter has at least 15ms.

Both things are helpful, but just the USB Patch wouldn't help out too much.
You can't get rid of the Adapter Lag without replacing it.

I think that these Parallel Port Adapters are laggy, too, but they seem to be better than normal USB Adapters.


-Scorpion-

[shocker]

ok, so besides changing the usb clock, there isn't anything else i can do to get rid of the lag?
and would changing the usb default clock slow my computer down in anyway? would it use my cpu or anything like that?

[-Scorpion-]

It shouldn't slow down your computer or anything.
Sry I don't know about other Tweaks, but if anyone else does,
please let us know ^^

Ah and there are also Parallel Port Adapters for 2 Pads available!

[shocker]

i know you can make a 2 port parallel adapter, but i know nothing about soldering or whatever. do you know anywhere you can buy one?

[-Scorpion-]

Since I'm from Germany I only know a German location:

http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&category=12831&item=5207043530&rd=1&ssPageName=WDVW

Sry don't know about other stores.