Hi all,
I'd like to get a 5 1/4 inch floppy working on my Ohio Scientific C1P-MF.
Since I only have one OSI 5 1/4 inch drive available, on my C4P-MF, I want
to get another working. OSI relied on the drive unit to provide data
separation, relatively easy to find on 8 inchers but seems to be pretty
tough to find on a 5 1/4. There is an old article describing how to build
a suitable data separator circuit available on a couple of sites on the web.
Seems pretty simple, just uses two chips a couple of resistors and a cap.
The problem is, I can't read the cap value. The best image I can find is
here:
http://www.technology.niagarac.on.ca/people/mcsele/images/SA400Disk1.jpg
You want to look at "Figure #3". I've used several different image
processing
programs, but I can't get the scribble next to the cap legible. I've looked
at the data sheet for the chip, but I don't know enough for an obvious value
to jump out at me. Part of the accompanying text says: "The RC time
constant
is adjusted to give an output pulse width on pin#1 of the 74LS121 of 5.5
ls."
I assume "ls" is an oddball abbreviation for microsecond?
Alternatively, does anybody have an MPI B51 or B52 with data separator
available for trade, or another design for a data separator?
Thanks,
Bill