[Lowfer] Re: Wish List

[Johan H. Bodin]

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