[Lowfer] Re: Wish List

[Mike Staines]

Thanks, Johan.
I know that Bill had to perform many tricks to get Africam working in pure 
DOS even with a GPS input to marshall events.
Perhaps it is possible to run an Africam "engine" under windows but I know 
that project is out of my league. 8-)

I'm having problems just getting windows to accept keyboard input under the 
timing constraints of a QRSS program.

73
Mike
wM1ke
----- Original Message ----- 
From: "Johan H. Bodin" <jh.bodin at telia.com>
To: "Discussion of the Lowfer (US, European, &amp; UK) and MedFer bands" 
<lowfer at mailman.qth.net>
Sent: Friday, November 30, 2007 4:14 PM
Subject: Re: [Lowfer] Re: Wish List


> Mike,
>
> you are right about the PC being a bad choice for critical real-time 
> applications. Even "pure DOS" is bad unless you disable the 18.2Hz timer 
> tick... However, if you use the soundcard with a suitable amount of audio 
> buffering, to provide some "time elasticity", time gaps in the processing 
> will not affect the end result and the timing will depend on the soundcard 
> sample rate alone. The only penalty is some delay caused by the buffering. 
> If the accuracy of the soundcard clock is not enough, you  can feed a TX 
> carrier (GPS disciplined or whatever) into the soundcard input and then 
> phase modulate that carrier to your hearts desire in software and then 
> send the result to the soundcard output. Any sampling frequency error will 
> be cancelled out since both input and output of the soundcard are 
> (hopefully?) using the same sampling clock. For RX, feed a high precision 
> LO (BFO) into one of the soundcard inputs and use that in the software 
> algorithms (the RX audio goes into the other channel).
>
> 73
> Johan SM6LKM
>
>
> Mike Staines wrote:
>> Warren (et al):
>>
>> Regarding your wish for an Africam windows GUI:
>>
>> After fooling around with Africam and not making much progress on your 
>> request for a windows wrapper, I contacted Bill DeCarle and recieved, as 
>> always, a nice note from him telling me why a windows GUI could never 
>> work. Believe me, there is a LONG list but it all comes down to timing. 
>> Africam requires very EXACT timing that can only be provided by a box 
>> running pure DOS. Even the time spent processing a key stroke has to be 
>> accounted for. Windows constantly interupts programs to clean shop, 
>> handle unrelated events and have a cigarette.
>>
>> But he encourged me to butt my head against the wall if I wished.
>>
>> Accordingly, I think I might still have a workaround that is a two 
>> computer solution: one to run Africam the other to run a GUI that talks 
>> to the first via serial port or a network connection. I'll work on that 
>> as soon as the swelling subsides.
>>
>> As for your request for a QRSS/DFCW program:
>> I have something up and running but I have one problem to overcome in the 
>> way that Windows handles keyboarding. Hope to have that tackled soon.
>>
>> 73,
>> Mike
>> wM1ke
>
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