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Old October 10th 14, 08:23 PM posted to rec.radio.amateur.homebrew
Lostgallifreyan Lostgallifreyan is offline
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First recorded activity by RadioBanter: Sep 2006
Posts: 613
Default Frequency accuracy in older RXs

Rob wrote in
:

For the specific function that you want, there also exist soundcards
with dedicated chips that can do that. In the early days they were
hardware designs, I think today's boards more often use a DSP to emulate
what the hardware did in the past.


Yamaha did a board with six large IC's on it, but it was very expensive, and
not very common. My I/O is cheap now, 30 quid where a grand was the original
cost! Sadly while it has exccelent MIDI and wave portage, its onboard DSP is
only for routing between local audio ports, and I doubt I can get at it.

Also note that when you need a lot of CPU power to do repeated and
duplicated tasks like that, a modern video card has the perfect
architecture for it. On NVIDIA cards, you can download and execute
software that you develop yourself using their CUDA development tools.
Maybe other video card manufacturers offer comparable tools by now.


That video board idea is nice. Presumably they're common and cheap too,
though I'm not sure if thsi will limit my choice of OS a lot. As it is my
existign hardware limits me to W98, and at a pinch WXP though Wine in Linux
might work.

The main problem with all these mthods is that if I have to add any
specialised hardware and methods, the number of buyers who'd say they cannot
use the synthesier would be about 96% of its likely market. Even staying
with W98 (or Wine) and advising people to buy any cheap old machine to run it
on, so long as it can do MIDI as well as audio, might put that percentage
much higher. I ought to learn some ASM after disassembling my own GCC
compiles too, because I suspect a lot might be improved that way in the fast
loop if I stay with i386 hardware.

Normal service may now be resumed bu those who want it. This was a tad
off-topic and long at that... I was just taking the opportunity.. I will look
at the FPGA, for sure, on the offchance that it allows a dramatic reduction
in the speed and complexity of the sontrol system.

Thanks, Rob, for that help. I'll save this thread.