[hpsdr] HPSDR / PowerSDR hardware selection

[Eric Blossom]

On Sun, May 25, 2008 at 07:02:09PM +0100, Michael White wrote:
> Hi Eric
>
> Great stuff regarding paging control. I would imagine there must be 
> something similar in the Windows API.
>
> Am I right in thinking that Linux uses a co-operative task scheduler?, I 
> remember from years ago working on a Unix system that ran a time slice 
> system and then depended on co-operative code to release the thread early.

No, linux and unix have been preemptive since the beginning of time.
The issue is at what granularity the kernel can be preempted.  There's
a real-time patch that makes it quite low.  IIRC, it's on the order of
a few microseconds.

> I have seen many embedded system boards coming through these days using 
> light weight Linux, (like uClinux),, but as I understand it, unix cannot be 
> made pre-emptive for true real-time purposes. But so much time has passed 
> since the days I was playing with Unix it could be that there is branch 
> that can act as an RTOS.

> I know the Analog Devices Blackfin processor is running uClinux as a viable 
> OS for DSP,. That  could be a really good open source platform for 
> Sasquatch with all the free toolchains.

The downside is that the Blackfin is a 16-bit fixed-point processor.

Eric

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