On 24/02/11 18:01, Steven Hirsch wrote:
I will look into it. Thinking out loud: I wonder if
the data format is
compatible with any of the open-source Catweasel code, or could be
converted in such a manner.
It could be, but you'd have to resample the data. Basically, it's one
floating-point multiply operation per transition.
CatweaselValue = DiscferretValue * (CatweaselClock / DiscferretClock)
CatweaselClock -- Catweasel acquisition clock rate, in Hz
DiscferretClock -- 100e6 (for the latest firmware)
DiscferretValue -- timing value from the DiscFerret
CatweaselValue -- equivalent value from a Catweasel
You'll be throwing away a fair amount of timing resolution, and you need
to be careful about timing overflows. Use the appropriate CatweaselClock
value to get the most resolution without the value clipping to 127.
If memory serves, the Catweasel starts counting from 0, in which case
you'll need a -1 on the end of that. The DiscFerret uses a stored byte
of '0' as a special value -- "the counter overflowed, add 127 to the
next count value". It actually counts from 1, i.e. "there was a 10ns gap
between the last two transitions". Bit 7 is still used for the state of
the INDEX bit, though if the group wishes, a config bit could be added
to use the entire 8 bits for timing data...
BTW, an 8" diskette written in M2FM (for Intellec
Isis) and two SD N*
10-sector diskettes are on their way to you.
Thanks for that -- I'll take a look at them when they arrive.
Thanks,
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/