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
>
> 
>



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