26 Nov
2009
26 Nov
'09
7:39 p.m.
> I have been told that that calls for dual-trace
and 20MHz or higher. Is
> that correct?
On Thu, 26 Nov 2009, Tony Duell wrote:
Only because that's about the loswst spec
you'll find in a modern 'scope.
I did try a number of times, but my lack of expertise (TOTAL IGNORANCE of
what I was doing) got in the way, and I trusted the advice of "experts".
But, it was still very useful and fun. I used both scopes for automotive
diagnosis. For example, it isn't very easy to find out that the problem
with an alternator ("just replace the whole thing!") was a diode (three
phase rectification) without a scope.
Eventually, I gave it to somebody who needed it more than I did, and I got
myself a used NLS 215. Still not enough for floppy drive alignment. But
Did you actually try to align a floppy drive with it? Actually, if you want to align floppy drives (and
nothing else), I would
try to find a thing called a 'Microtest'. It's a box containing an ADC
and a microcontorller that links to a PC serial port (_Any_ PC with a
floppy controller and a serial port, I think you need 256k RAM and any
display adapter, even MDA). You link up the drive under test as drive B
on the PC, and run the software that comes with the microtest. Then
select the drive from the menu (and there's every one that _I've_ ever
wanted to work on), it drwas a picture of the drive PCB (using IBM
line-drawing characters) and tells you where to conenct 5 clip-leads from
the ADC box. Then put in a standard analogue alingment disk and it will
tell you how far off-track you are, if the track 0 sensor is correctly
positioned, and so on.
That sounds sweet, and likely out of my price range.
I liked using the Dysan Digital Diagnostic Disk, and wrote some code for
additional unsupported machines, but I could never shake the feeling that
I wasn't able to do as good a job as an analog alignment.
Can you
imagine what the world would be like if NLS had gotten into making
computers? :-) They'd probably grow faster than they could manage, and
I
assume that is very much tongue-in-cheek...