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

  ----- Original Message ----- 
  From: kd4e 
  To: [email protected] 
  Sent: Thursday, September 14, 2006 3:23 AM
  Subject: Re: [digitalradio] Re: ARQ sound card modes


  > TKS for all the answers and the adress. 
  >> it requires 20 ppm or better...
  > 1/50.000, hum it's not reasonnable for a standard PC (more about 1/3000).
  > 73 Patrick

  Is the 1/3,000 limit caused by the MS version of windows
  or is there some other limiting factor?

  Memory, CPU, buffer size, 64-bit vs 32-bit, etc?

  Might one see improved performance with a different
  operating system, Apple or Linux?

  -- 

  Thanks! & 73,
  doc, KD4E
  ... somewhere in FL
  URL: bibleseven (dot) com


   

[Non-text portions of this message have been removed]



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/
 



Reply via email to