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| TurboTwist Hi-Low Spinner Backspin problem. XP 64 Poll rate, Works Now! |
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| Todd H:
Just tested the TT2 with Arkanoid. Perfection. And Tempest at a setting of 6 feels exactly as I remembered. Great product Randy! :notworthy: |
| robertsig:
OK, I have to reply to this because I'm having the same problem. I have a TT2 master and slave (X & Y axis on mouse). My MAME machine is running XP 32-bit SP3. I have the USB interface. I set Tempest's analog down to 6, as well as trying a bunch of other settings. Standard polling rate of 125 on usbport.sys. I also upped to to 250 and 500 for testing. In all three cases, I still get backspin, or at least that is what I think it is called. The "claw" jitters back and forth instead of spinning if I move the spinner fast. What do I do next? Out of the hundreds of games I have, Tempest was my #1 reason for building this thing. |
| MonMotha:
The USB spec restricts low speed (1.5Mbps) devices to 100Hz polling rate. They are not permitted, per the words of the spec, to ask for anything higher, though there's nothing technically stopping them from doing so. For HID devices, Windows "upgrades" them to 125Hz, since 100Hz is lacking in many uses such as gaming, regardless of what they ask for. Linux seems to do something similar. What these hacks do is cause Windows to "upgrade" things even more for low speed devices. Some poorly done versions of the hack also apply themselves to full speed devices which can actually cause such devices to be slowed down! The USB specification does not restrict full speed (12Mbps) devices. They are permitted to request any polling rate that is an integer divisor of 1000Hz (they actually specify the polling PERIOD in milliseconds) in their descriptor. Windows seems to respect the devices wishes. I've asked for 1000Hz before, and Windows complies. Modern Linux kernels also comply fully, but some older ones max out at 500Hz or sometimes some weird number like 800Hz. Usually, 250Hz is more than sufficient even for the most picky of gamers. Most games only poll button and joystick inputs once per (60Hz) frame, anyway. However, on device that report relative movement, such as mice and trackballs, one has to worry about the relative motion counter overflowing (which causes backspin). To counter this overflow, one can do two things: increase the polling rate (resetting the counter more frequently so it doesn't have a chance to overflow) or making the counter bigger (so that it takes longer to overflow) Note that both low speed and full speed are part of the USB 1.1 specification. A USB 2.0 device can also be low speed or full speed. "Full speed" always refers to 12Mbps, NEVER to the 480Mbps "high speed" introduced in USB 2.0, even if a device is USB 2.0 compliant. High speed (480Mbps) devices, which must be USB 2.0, can request much faster polling rates as they request their polling rates in units of 125microseconds. Very very few HID devices are high speed. Usually only composite devices with some other function (such as a mouse with integrated flash storage or something similarly weird) in addition to the HID would be high speed. I'm not aware of any commercially available "arcade IO" devices on the market that are high speed, and it's generally unnecessary. Note that high speed devices are supposed to degrade gracefully to full speed if at all possible. Most do (e.g. storage devices get slower, cameras use lower framerates, etc.). Also note that high speed is faster than full speed. Put another way, full speed is slower than high speed. Yes, it's totally unintuitive, but welcome to the world of a hardware standard written by Microsoft and a software standard written by Intel...all while doing who knows what drug(s). |
| robertsig:
Ugh. I was changing the wrong value. I changed sensitivity down the 6% and it works fine. |
| MonMotha:
FYI, since what I said above is not obvious if you read certain parts of the USB spec, e.g. the description of the "endpoint descriptor" would lead you to believe that both full and low speed devices can ask for anything between 1-255ms polling periods, see page 51 of the USB 2.0 specification: --- Quote ---A full-speed endpoint can specify a desired period from 1 ms to 255 ms. Low-speed endpoints are limited to specifying only 10 ms to 255 ms. --- End quote --- |
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