rec.autos.simulators

by **Tony Jeste** » Sun, 11 Mar 2001 14:59:58

Ken MacKay posted this link in an above message:

http://www.racesimcentral.net/

It explains how to adjust the Windows registry to fine tune the PDPI L4 for
your particular controller pots. By following the instructions, I found my
settings were WAY off. I always new something was wrong, and suspected
something like this, but I never knew how to fix it. I don't understand why
there was never any info in the PDPI documentation about it. It took close
to an hour to get it dialed in perfect with all the necessary re-boots, but
WOW, what a difference. Especially in the brake pedal. Before I got a max
raw number in GPL calibration of 66 for my brake pedal. Now it is 246. The
difference in brake pedal feel is amazing. Much, much more controllable.
The steering was a lot closer initially, but now that it is almost perfect,
the car seems more stable. I ALWAYS have had a hard time holding an exact
line like near the edge of the track on a fast straight. Now I think the
car is more stable, it doesn't want to wander as much.

These other links of his are very interesting also.

If you have a L4, you need to check this. I only wish I had done it sooner.

-Tony-

by **Tony Jeste** » Sun, 11 Mar 2001 15:03:50

Here is the other link:

http://www.gplonline.com/tech-talk/hardware-tech.htm

by **Andrew** » Sun, 11 Mar 2001 16:51:45

I found this article the other day via a usenet search. My question is
this... the values that I get for my accelerator and gas pedals are roughly
87-180 (approx range of 100). Obviously this is less than the theoretical
limit of 255, but it would seem to me that I'm simply not using the full
range of the pot therefore my values are smaller. That is depressing my
pedals doesn't turn the pot sufficiently to generate a larger value. Is
this correct, or do I need to sit iin front of my PC for an hour trying to
get a larger range of values?

by **Stephen Smit** » Sun, 11 Mar 2001 22:52:35

There are only two ways to 'fine-tune' yer PDPI: either edit the Registry or
change the pot values by changing the pot itself. (You *might* be able to
run a variable shunt across the pot, like the trimmers on a CH FlightStick,
but I haven't tried it.) Editing the Registry, altho tedious and dangerous,
like defusing a bomb, is probably preferable. But even if you don't have
exactly the right binary values in the Registry, it doesn't neccessarily
mean you're not 'seeing' the full range of the pot's resistance, it merely
means the increments are not as fine as they could be. That is, with coarse
values, the resistance will change more jumpily as you twist the pot...but
the PDPI's built-in anti-jitter will smooth most of this out.

--Steve Smith

> I found this article the other day via a usenet search. My question is
> this... the values that I get for my accelerator and gas pedals are
roughly
> 87-180 (approx range of 100). Obviously this is less than the theoretical
> limit of 255, but it would seem to me that I'm simply not using the full
> range of the pot therefore my values are smaller. That is depressing my
> pedals doesn't turn the pot sufficiently to generate a larger value. Is
> this correct, or do I need to sit iin front of my PC for an hour trying to
> get a larger range of values?

> > Ken MacKay posted this link in an above message:

> > http://simracingmag.gameloft.com/articles/tweaking/00q4/niels1.shtml

> > It explains how to adjust the Windows registry to fine tune the PDPI L4
> for
> > your particular controller pots. By following the instructions, I found
> my
> > settings were WAY off. I always new something was wrong, and suspected
> > something like this, but I never knew how to fix it. I don't understand
> why
> > there was never any info in the PDPI documentation about it. It took
> close
> > to an hour to get it dialed in perfect with all the necessary re-boots,
> but
> > WOW, what a difference. Especially in the brake pedal. Before I got a
> max
> > raw number in GPL calibration of 66 for my brake pedal. Now it is 246.
> The
> > difference in brake pedal feel is amazing. Much, much more
controllable.
> > The steering was a lot closer initially, but now that it is almost
> perfect,
> > the car seems more stable. I ALWAYS have had a hard time holding an
exact
> > line like near the edge of the track on a fast straight. Now I think
the
> > car is more stable, it doesn't want to wander as much.

> > These other links of his are very interesting also.

> > If you have a L4, you need to check this. I only wish I had done it
> sooner.

> > -Tony-

by **Andrew** » Mon, 12 Mar 2001 01:19:46

I went back and reread the article and made the suggested changes to my
registry. I didn't get the "perfect" range of values, but I did manage to
fine tune the range from ~100 to ~220 for my pedals. I've always had a fair
amount of jitter with the pots on my pedals. The amount of jitter varies
depending upon the time of day, lunar cycle, etc, but after I did the fine
tuning the jitter has vanished. Which is very odd.

-Andrew

by **Stephen Smit** » Mon, 12 Mar 2001 04:56:57

Andrew,

You shouldn't have *any* jitter with a range of 100-220 (mine, currently, is
abt. 70-240 w. the wheel; abt. 15-190 w. the pedals) and a PDPI. When you
look at the Test screen in Windows, do you see any jitter w/o moving the
wheel or pedals? Do you see any jerkiness when you move the wheel/pedals
smoothly from one extreme (lock-to-lock, or none-to-full throttle) to the
other?

In GPL, you have to select the Windows joystick driver (.vxd) in order to
see the benefits of the PDPI, not the Papy driver (which shows much larger
#s).

If it still jitters, try moving the connector around (one port to the other)
or moving the slider switch.

Let me know how it works out.

--Steve Smith

by **Andrew** » Mon, 12 Mar 2001 06:51:30

I wasn't clear about the range of values that I'm now receiving. I've tuned
all my pedals to be approx 15-250. Previously they were something like
80-180. So I've doubled the range that is being reported by the PDPI,
DXTweak. GP3 and GPL. I've always had jitter even with the PDPI, after
'fine tuning' it has completely disappeared. When I received my PDPI a year
ago, I was dissapointed because it didn't solve my jitter problems. Now it
appears to have been a pot-wheel issue. Maybe when toying with the pots I,
managed to alleviate some stress on the shafts that was causing the jitter.

I've recalibrated my wheel in GPL and GP3 and both are rock steady. The
funny thing about GPL is that I've never noticed that the PDPI card has done
much for frame rates. On the other hand, GP3 benefits greatly. I think
that Papy has done a better job in balancing how the gameport is polled.
That being said, I'm not sure how much control Direct Input allows for
polling the gameport.

-Andrew

by **Ken Macka** » Mon, 12 Mar 2001 20:19:29

<snip>I've recalibrated my wheel in GPL and GP3 and both are rock steady. The

What are you running for a system? If GPL is limited by the video card then
freeing up the CPU may not make much difference (although I would've thought GP3
would require more from the video than GPL). From my tests, the cpu (cel 400) is
the bottle neck on my system so I hoping an L4 we help with GPL until I can
upgrade the CPU.

Ken

by **Stephen Smit** » Tue, 13 Mar 2001 03:56:54

Ken,

Where are you planning on finding an L4?

Andrew,

Good to hear your jitters are calmed. I still think a good PDPI setup beats
FF, altho I never got quite used to FF (it can help 'train' you to drive
more accurately...if you've the patience).

--Steve

> <snip>I've recalibrated my wheel in GPL and GP3 and both are rock steady.
The

> > funny thing about GPL is that I've never noticed that the PDPI card has
done
> > much for frame rates. On the other hand, GP3 benefits greatly. I think
> > that Papy has done a better job in balancing how the gameport is polled.
> > That being said, I'm not sure how much control Direct Input allows for
> > polling the gameport.

> What are you running for a system? If GPL is limited by the video card
then
> freeing up the CPU may not make much difference (although I would've
thought GP3
> would require more from the video than GPL). From my tests, the cpu (cel
400) is
> the bottle neck on my system so I hoping an L4 we help with GPL until I
can
> upgrade the CPU.

> Ken

by **Mark Gra** » Tue, 13 Mar 2001 16:45:50

>Ken,
>Where are you planning on finding an L4?

I ordered a new L4 a couple weeks ago from Act-Labs:

http://www.actlab.com/pdpi_l4.htm

--
" Why bother..." - R. Crumb

by **Stephen Smit** » Tue, 13 Mar 2001 22:48:33

Really? That's great! I didn't know Act picked up the torch. I mean, PDPI
*is* outta bidness, innit?

--Steve

> >Ken,

> >Where are you planning on finding an L4?

> I ordered a new L4 a couple weeks ago from Act-Labs:

> http://www.actlab.com/pdpi_l4.htm

> --
> " Why bother..." - R. Crumb

by **Mark Gra** » Wed, 14 Mar 2001 00:38:51

>> I ordered a new L4 a couple weeks ago from Act-Labs:
>> http://www.actlab.com/pdpi_l4.htm
>Really? That's great!

Yeah, I'm having a new rig built & insisted it have a PDPI installed.

I'm still digging around for a post someone made to r.a.s. concerning
the latest drivers for the L4.

IIRC, Act-Labs bought out PDPI about a year ago. Unfortunately, the
Tech Support phone number listed at the Act-Labs site is a no go. I
was going to give Mike Pelkey (sp) a call regarding those new drivers.

Maybe the new drivers were on the CD I received, but I shipped it off
to Falcon Northwest before I had a look.

Might want to bag a backup L4, Steve. I don't know if they're still
building the things or simply selling off the current stock.

--
" Why bother..." - R. Crumb

rec.autos.simulators

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