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PDPI L4   By Gordon Berg
  In this day and age of the Pentium II 400, most gaming PCs are still using technology that is 15+ years old -- the analog gameport (as found on all ISA based sound boards). If you're like me, you've had a real love/hate relationship with gameports, gamecards, and anything that interfaces with them.

It's incredibly aggravating to realize your precision hi-tech joysticks, throttles, and rudder pedals have been crippled by something so inefficient, so vestigial. Many claim Win98 and USB will save the day. However, while we all hope this to be true, I'm of the opinion it will be a good year from now before we see that kind of market develop sufficiently (I'm sure the announcements at the upcoming E3 will be to the contrary).

In the meantime, I think I've found something that will not only prolong the investment of your expensive gear, but will most likely boost the performance of your gaming experience as well -- PDPI's Lightning 4 gamecard.

Warbirds 3d
Warbirds 2.01

Not too long ago, a little known gaming peripheral was getting quite a bit of attention in the Warbirds newsgroups. I stumbled across discussion of the L4 quite by accident after I missed Lloyd Case's brief review of this product back in CGW's March issue. Curious, I ordered the card to see for myself what all the fuss was about. Hallelujah, I have seen the light! Want to increase your framerates? Pssst, come here, I've got something to show ya.

As you might have already surmised, the L4 utilizes a digital gameport, not an analog one. While I won't even pretend to understand how it works, I do know the resulting process frees up your CPU cycles by a staggering amount. On an analog gameport, as much as 50% of your CPU time can go towards polling your joystick -- time that could be much better spent running your game. Time for a change!

With the L4, the required CPU time has been reduced to an amazing .18% (yes, less than one fifth of one percent). Needless to say, such an increase in available horsepower translates to faster framerates, which thrilled me to no end.

One of the saddest days of my life was finding out just how slow I was running Jane's F-15. My system is starting to show its age: It's only a P166 -- overclocked to 200, non-MMX -- with 48 megs of RAM and a Monster3D. After enabling the fps counter in the f15keys.ini file, I found I was getting a measly 15 fps! I switched to a PCI sound card and got it up to 18 fps (hey, every little bit helps). Then, once I added the L4, my fps jumped up to 32. Not bad, huh? Yes, you read that right, my frame rate DOUBLED by adding this digital game port! And that's not all...

When Windows95 was in development, Microsoft came across what became known as "Bug 1541." The essence of 1541 is that when you use a joystick in a game being played over a modem under Win95, data packets will get dropped if the joystick is polled with interrupts disabled. Depending on the game played, such a loss of data often lead to crashes to the desktop, as well as poor connectivity and increased lag. What to do?

Microsofts's solution was to introduce the now infamous, "Poll with interrupts enabled" option in the game controller applet, much to everyone's confusion. If you've tried to use your joystick with this option turned on, then you understand when I say this caused a periodic "spiking" of the joystick, often rendering a game unplayable (but hey, you weren't dropping packets!).

The L4, of course, eliminates this bug altogether instead of making a bad problem worse, like Microsoft did. This is especially good news for those of you who play your sims online: not only should you see an increase in framerates, but a more stable game experience as well. So, if we were to define a "killer app" for the L4, Warbirds is an awfully good candidate since the quality of the connection is so crucial to the experience.

Before the L4, I would crash to my desktop often and see more than a fair share of warping. Not only did such problems go away once I installed the card, but the enemy planes I shot at warped and jinked much less, and my framerates in the 2D version doubled (I went from 20 fps in Range 1 to 40 fps in Range 3. This was tested extensively in version 2.0r6, right before 2.01 came out.) Alas, even this card can't save my poor fps in the new 2.01 3D version. There are just some things in this world that only a Pentium II 400 MHz will fix . Oh, and despite the fact that I now line up a far more stable target, nothing will help with my poor gunnery. :)

MS Combat Flight Simulator
Microsoft Combat FS

Warbirds, obviously, isn't the only online game that will benefit from the L4. Air Warrior, Confirmed Kill, Fighter Ace.. any online sim should benefit. At the very least, anything that needs a modem won't drop packets, which is always a good thing.

However, the L4 might not be everyone's panacea. I can only assume any game I play that uses a joystick has improved, but short of seeing an actual dedicated fps display to verify this, it's really hard to tell (and two of the games I own with fps counters haven't increased much, if at all -- Flying Corps Gold and Air Warrior 3)

Click to continue . . .

 

F15 Formation

I'd like to think that it's smoother in games such as Longbow 2, Red Baron 2, Interstate '76, and Mechwarrior: Mercs, but that just might be wishful thinking on my part. After all, I might only be running at 200MHz, but maybe the halved available processing time was enough power for these other titles when I was using an analog port. Nonetheless, future sims are going to want all you can give them, so it'd be prudent to offer these games-to-be as much CPU cycles as possible, and the L4 clearly helps in that area. Falcon 4, anyone?

Just like any other gaming product, it's possible the L4 might not work with your computer. A few in the WB newsgroups reported they couldn't get the card to work in their systems, and I know of two fellow journalists who also couldn't get these cards to respond (Ed. Note: I myself was given a VERY early board and am now waiting for a replacement) so the jury is still out as to how compatible the L4 will be across the diversified PC gaming landscape.

However, PDPI has very good (and attentive) tech support; if the card ultimately dissappoints, they'll issue a refund (it's not like anyone is going to be stuck with it should the L4 not work). One final negative about the L4 is in the area of compatability -- it won't work with every joystick out there. To quote Mike Pelkey of PDPI:

"Any 'digital' game controller that has been designed to use the standard gameport in a non-standard way will not be compatible with the L4. Examples of this type of controller include the Microsoft Precision Pro, the Microsoft Force Feedback Pro, the Gravis GRip or the Microsoft Sidewinder Game Pad. The mainstream joysticks -- the CH Products and Thrustmaster type products, including those with programmable 'digital' functions passed through the keyboard or serial port interface are perfectly suitable for operation with the L4. Note that this includes the vast majority of game controllers, such as the Suncoms, Saiteks, QuickShot, etc."

Also note that the original Microsoft Sidewinder 3D will work with the L4 since it has an "analog" mode. Furthermore, driving wheels by TM can sometimes be a problem too because the values in a TM wheel are different from what is typically found in an analog joystick. I couldn't get my Grand Prix 1 to work, and I haven't had time to hack the registry yet to input the values that might make my wheel responsive. PDPI is aware of the problem and say the problem should be fixed in the next driver release.

CK
Eidos Confirmed Kill

The future is looking even brighter for the L4. To further quote Mike Pelkey:

"The next version of the driver, revision 1.4, will incorporate an innovative mapping scheme to allow the selection of any of the devices interfaced to the L4's four game port channels for the primary game controller. This feature will allow a gamer to install and calibrate a variety of game controllers such as a HOTAS system on channel one, a wheel and pedals on channel two, a flight yoke and rudders on channel three and a game pad on channel four.

A simple tag will be invoked when each game application is launched, mapping the desired controller into the primary game controller slot. The purpose of this extention to the L4 driver is to promote more usefulness to the multi-channel architecture of the L4 for normal game applications. Simultaneously active multiple controller applications will continue to be supported. Up to eight full-featured game controllers may be supported with a two-card installation."

What this means in English is that the L4 will shortly become the equivalent of CH's SwitchBox or the venerable JoySwitch when the next set of drivers become available. Furthermore, the technology implemented in the L4 will become the basis of a future line of USB controllers to be released by PDPI as well. But until then, why not turn your beloved analog gear into a psuedo-USB setup today? Best hundred bucks I ever spent...

Editor: How does the L4 digital port compare to the digital port on the Turtle Beach Montego or the Diamond Monster Sound (the TB Daytona port is speed compensated but NOT digital)? Preliminary tests show the TB Montego about 66% of the speed of the L4, but with more jitter. The Diamond Monster Sound is actually slightly faster than the L4 (at the price of stability). But the numbers are so low already (.18% CPU usage) that anything lower becomes transparent to the user. You won't experience any difference in frame rate.

Like the Turtle Beach, the Monster Sound lacks the precision of the L4 and has also proven glitchy when reading joystick buttons. In fact, it seems to be worse than the Turtle Beach. You might not notice this in a flight sim, but when you are three feet from the wall in your Ferrari in a driving sim the precision of the L4 is a joy to behold. You will have precise control like you never experienced before. Why is this so? For the technically inclined, check out this Technical Briefing.

Will the L4 allow use of BOTH sides of the SUNCOM throttle PLUS a rudder control? Yes! It seems to be the only single solution on the market for this configuration so far, though only Fighter Squadron and Fighter Duel 2 are supporting the split throttle so far as I know.

What do you do if you own a Diamond Monster Sound and want to disable the game port on the Diamond board? You can't. What you must do is uninstall the MSound, and then install the L4, selecting the driver in the Controller applet etc. When you reinstall the MSound the PnP feature should assign the MSound to a different address.

What about a dedicated game card like that made by CH or Thrustmaster? While these cards eliminate some of the jitter associated with the old analog ports they are still S L O W as molasses. The best alternative is a product like the L4, digital with high quality components. Note however that the L4 will NOT work with purely digital devices: MS Precision Pro, MS Sidewinder Gamepad, Gravis Grip, MS FF Pro.

Visit the PDPI web site at www.pdpi.net

 

 

 

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