31 Oct
2008
31 Oct
'08
3:05 p.m.
On Fri, Oct 31, 2008 at 09:16:47PM +0000, Tony Duell wrote:
I agree that a 50MHz digitizer is not a trivial device, but if it would
still work backed down to 25MHz or even a little slower, say 4x or 5x
the rate of the raw stream, there'd be a lot more margin to work with,
especially with modern high-speed microcontrollers like the Dallas
DS89C450-MNG.
You still need a local storage system fast enough to handle the bits once
they are collected and possibly partially analyzed/reduced. That's one
arena in which a rotating disk is simpler than many solid-state solutions.
-ethan
--
Ethan Dicks, A-333-S Current South Pole Weather at 31-Oct-2008 at 22:00 Z
South Pole Station
PSC 468 Box 400 Temp -53.9 F (-47.7 C) Windchill -79.6 F (-62.0 C)
APO AP 96598 Wind 6.9 kts Grid 9 Barometer 676.5 mb (10761 ft)
Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html
> ISTR the
bitrate from a ST412 drive was about 5 MHz...
The obvious thing to do is to sample the data stream (either from the
controller wehn writing/formatting, or from a good drive if you want to
copy it) at about 10 times the data rate (that's where the 'high speed'
requirement comes from) and record it in flash memory or something. Then
replay it back to the cotnroller for reading. It's doable, but getting it
all working at 50MHz is not going to be trivial.