Your characterization of Linux as further from real-time than older operating systems is inaccurate, Rick. See
http://linuxdevices.com/articles/AT8073314981.html http://www.mvista.com/products/realtime.html http://www.realtimelinuxfoundation.org/ http://source.mvista.com/linux_2_6_RT.html http://www.timesys.com/ 73, Dave, AA6YQ --- In [email protected], KV9U <[EMAIL PROTECTED]> wrote: > > It is kind of ironic that MS-OS and Linux-OS are further from Real Time > OS's than the older software. But even with a +/- 10 ms time (worst case > 20 ms from one extreme to the other), wouldn't you just have to have a > little bit longer "window" than existing ARQ modes in order to succeed? > > I think the main thing I am asking is ... how long a window do you need? > Pactor uses a 170 ms. idle time. Since the timing from a computer (20 > ms maximum error) is not able to switch a transceiver fast enough for > Pactor, would 20 times longer than the maximum error be enough? Ergo, > 20 x 20 ms = 400 ms window or idle time? > > 73, > > Rick, KV9U > > > Patrick Lindecker wrote: > > >Hello, > > > >When we were on MS-DOS PC (good old time HI), the clock (and all the hardware in fact) was accessible by program (through registers) and it was easy to determine the error of the PC cristal. I measured in several MS-DOS PC an error of more or less 1/3000, which was not very good, but I suppose it was not really indipensable to be precise for a PC. > >I suppose that the modern PC have the same relative uncertainty. > > > >I have seen, thanks to Sholto G7TMG, that under Windows the time can be very precise (down to 100 nanoseconds) but only 64 times by second, and there is no interpolation between each sample. So the uncertainty in a Windows PC is +/- 7.81ms which rules out ARQ Pactor and Amtor in a Windows PC. > > > > 73 > >Patrick > > > > > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
