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fulfern

Gameport and DPC latency tool

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Hi all.My system is a Q6600 3GHz, 4GB ram, 8800 GTX 768MB, W/XP 32 bit SP3.Joystick/throttle/pedal combo is a Thrustmaster F22+TQS+CH ProPedals (all the stuff is the old gameport version).- The F22+ TQS+CH ProPedals (rudder) are connected through a Sound Blaster live! card, of which I use only the gameport, with SB sound disabled via device mgr (see picture).- The CH toe brakes are connected through a USB/gameport adapter.All is perfectly working, without any stutter (FSX SP2).Yesterday I tried DPC latency tool with FSX running and discovered, much to my surprise, that latency values were very high (some 2000 microseconds) with the joystick connected.Then I disabled the gameport in device mgr and the latency values dropped to some 10-20 microsecond.The system, with the gameport disabled, seemed more "snappy" when changing views, etc.Of course the culprit is the SB gameport, as the other USB/gameport adapter was still connected and didn't give any problem.Any idea, ...apart from wasting all my hotas setup and buying a new USB version ?Thanks in advanceFulvio

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Hi fulfern,I'd never really thought about it, but a gameport would show up with "high latency". The gameport was really a set of four timers that were controlled by the position of the joystick handle. The standard time was about 1000 microseconds. The joystick read routine would start the timers, and then measure the time it took for them to run. That time was taken as an indicator of the stick position, the calibration routine lined it up with what Windows needed to see. In the process, it would end up tying the PCI bus up for however long that took and it could easily hit 2000 uS since you've got 3 controllers plugged in. USB periodically moves all the data in one quick packet for each controller so the latency there would be much lower.No way to really do anything about it, and the latency can certainly affect the operation of other components in some cases, but if it's not causing you problems it there's probably nothing actually "wrong" with what's happening. It's just the nature of the beast.Best regards,- BobThe StickWorkshttp://www.stickworks.com

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Hi fulfern,I'd never really thought about it, but a gameport would show up with "high latency". The gameport was really a set of four timers that were controlled by the position of the joystick handle. The standard time was about 1000 microseconds. The joystick read routine would start the timers, and then measure the time it took for them to run. That time was taken as an indicator of the stick position, the calibration routine lined it up with what Windows needed to see. In the process, it would end up tying the PCI bus up for however long that took and it could easily hit 2000 uS since you've got 3 controllers plugged in. USB periodically moves all the data in one quick packet for each controller so the latency there would be much lower.No way to really do anything about it, and the latency can certainly affect the operation of other components in some cases, but if it's not causing you problems it there's probably nothing actually "wrong" with what's happening. It's just the nature of the beast.Best regards,- BobThe StickWorkshttp://www.stickworks.com
Bob, thank you very much for the explanation.Just a question, as you are a guru of F22/TQS stuff, if I remember (digital modification for F22...)I've fully programmed my F22 (undocumented functions included, X buttons etc...) and I would like to to keep the possibility of modifying my joystick assignments in the future.If I replace the sound blaster by another USB/gameport adapter, like the one I'm currently using only for toe brakes, will I be able to download the new programs on the F22 via thrustmaster software?Thanks and regardsFulvio
Why not replace the SB Gameport with another USB Gameport adapter? (They are very cheap...)Just found these two via Google:2-Axis ($15): http://sewelldirect.com/USB-to-Gameport-Ad...nd-Gamepads.asp4-Axis ($22): http://sewelldirect.com/Manhattan-Joystick...er-DB15-USB.aspCheers,- Jahman.
Jahma,thank you for the tip.Provided that I keep the possibility of programming the F22, it could be a viable solution.CheersFulvio

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Hi Fulvio,>> thank you very much for the explanation. <<You're quite welcome!>> Just a question, as you are a guru of F22/TQS stuff, if I remember (digital modification for F22...) <<Yes, the SWF22 Digital Chips. I wrote the code in the original chips, too.>> I've fully programmed my F22 (undocumented functions included, X buttons etc...) and I would like to to keep the possibility of modifying my joystick assignments in the future. If I replace the sound blaster by another USB/gameport adapter, like the one I'm currently using only for toe brakes, will I be able to download the new programs on the F22 via thrustmaster software? <<You can with some limitations. Under Win95 and Win98, the original software would download from Windows without any problems. In Windows 2K and XP 32-bit, the sticks would generally still work, occasionally there were problems with new keyboard ports. Windows itself wouldn't allow the software to talk to the keyboard port to do the download though, so you needed to boot a DOS floppy and run the download from there. You really only needed the F22Load.exe files, any text editor would work for the files. Once it was downloaded you could switch back to 2K/XP and usually it was still okay. Sometimes the chipset keyboard hardware would be incompatible and the machine needed to be using AT/PS2 keyboard and Serial/PS2 mouse, but once the download was done it would stay loaded and things generally worked pretty normally. I never tried programming one and then passing the axes through a USB converter, offhand I can't think of any reason it wouldn't still work as a 4-axis stick that way.I put the SWF22 chips together in 1999 to allow the download from Win2K/XP. They didn't use the keyboard port and so Windows didn't mind, but by about 2004 they were starting to have a little trouble with some of the more modern hardware (video cards and such) making it difficult to get a reliable read so I stopped making them.XP64, Vista, and Win7 don't offer gameport support at all, really. If you look, there is no "Add" button in the game controllers applet, the controller has to be plug and play which basically means USB at this point. The converters show up as USB sticks. The SWF22 chips won't work through the converters at all. Even if they could get the data through the converter, they'd be trying to talk to the gameport drivers that aren't there anymore.So, it really depends on what OS you want to use it with and probably whether or not you're willing to deal with the DOS boot floppy more than anything. When the keyboards and mice start turning up only in USB (it's already difficult to find a PS/2 mouse), that will probably be the end of them. Things work so much differently today than they did back in '96 when the F22's were released, they're probably having trouble functioning much at all on the late OS versions anyway.Hope that's some help!Best regards,- BobThe StickWorkshttp://www.stickworks.com

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Hi Fulvio,>> thank you very much for the explanation. <<You're quite welcome!>> Just a question, as you are a guru of F22/TQS stuff, if I remember (digital modification for F22...) <<Yes, the SWF22 Digital Chips. I wrote the code in the original chips, too.>> I've fully programmed my F22 (undocumented functions included, X buttons etc...) and I would like to to keep the possibility of modifying my joystick assignments in the future. If I replace the sound blaster by another USB/gameport adapter, like the one I'm currently using only for toe brakes, will I be able to download the new programs on the F22 via thrustmaster software? <<You can with some limitations. Under Win95 and Win98, the original software would download from Windows without any problems. In Windows 2K and XP 32-bit, the sticks would generally still work, occasionally there were problems with new keyboard ports. Windows itself wouldn't allow the software to talk to the keyboard port to do the download though, so you needed to boot a DOS floppy and run the download from there. You really only needed the F22Load.exe files, any text editor would work for the files. Once it was downloaded you could switch back to 2K/XP and usually it was still okay. Sometimes the chipset keyboard hardware would be incompatible and the machine needed to be using AT/PS2 keyboard and Serial/PS2 mouse, but once the download was done it would stay loaded and things generally worked pretty normally. I never tried programming one and then passing the axes through a USB converter, offhand I can't think of any reason it wouldn't still work as a 4-axis stick that way.I put the SWF22 chips together in 1999 to allow the download from Win2K/XP. They didn't use the keyboard port and so Windows didn't mind, but by about 2004 they were starting to have a little trouble with some of the more modern hardware (video cards and such) making it difficult to get a reliable read so I stopped making them.XP64, Vista, and Win7 don't offer gameport support at all, really. If you look, there is no "Add" button in the game controllers applet, the controller has to be plug and play which basically means USB at this point. The converters show up as USB sticks. The SWF22 chips won't work through the converters at all. Even if they could get the data through the converter, they'd be trying to talk to the gameport drivers that aren't there anymore.So, it really depends on what OS you want to use it with and probably whether or not you're willing to deal with the DOS boot floppy more than anything. When the keyboards and mice start turning up only in USB (it's already difficult to find a PS/2 mouse), that will probably be the end of them. Things work so much differently today than they did back in '96 when the F22's were released, they're probably having trouble functioning much at all on the late OS versions anyway.Hope that's some help!Best regards,- BobThe StickWorkshttp://www.stickworks.com
Bob,Really I forgot to tell that :- I have a standard, unmodified F22/TQS combo- At present, I use W/XP pro 32 bit, so when I want to download a new program onto the F22, I already have to boot my PC in pure DOS (I use a DOS bootable USB key, instead of the old floppy). In the past, withW95/W98, I used a simple DOS window, but as I do not reprogram my F22 so often, it's not a big problem.- I'm still using a traditional PS2 keyboard (an old MITSUMI, still with the big PS2 plug...) connected to the PC trough the F22, and I think this is the only way a programmed standard F22 can emulate keystrokes and send them to the PC.- I no longer use a serial mouse through the TQS -->PC, so I've lost the possibility of moving the cursor via TQS, but I don't miss it.My question was:Let's suppose that I connect my F22/TQS/CH propedal via a USB/gameport adapter, and keep the connection "PS2 keyboard" --- "F22" --- "PC". When I boot in DOS (as I already do) and try to download a new program to the F22 by using F22Load.exe (I'm using the last version that worked also with "new" pentiums) does it work?As far as I know the "compiled .F22 files" are downloaded to the F22 via the keyboard link, so there shouldn't be problems, provided of course that I keep the "keyboard -- F22 -- PC PS/2 port connection".By the way, the F22/TQS chips need an electrical supply, and I think they take it from the 5V pin of gameport port.In any case I should verify that the USB/gameport adapter emulates also this feature.Again, thaks for your timeRegardsFulvio

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