[comp.sys.cbm] Which disks to use with 1571

iachetta@ec.ecn.purdue.edu (Richard N Iachetta) (04/28/91)

What are the best kind of disks to use with a 1571 in 128 mode, double sided
single density or double sided double density?  I am having problems formatting
and using some brand new double density disks, and I am thinking that maybe
I need single density.  I know with IBM's you will have trouble if you double
density when you should have used single and vise-versa, and I assume it is
the same for the Commodore, but there is no mention of which type to use in
the 1571 User Guide.  Thanks.

Rich
iachetta@ecn.purdue.edu

rknop@nntp-server.caltech.edu (Robert Andrew Knop) (04/28/91)

iachetta@ec.ecn.purdue.edu (Richard N Iachetta) writes:

>What are the best kind of disks to use with a 1571 in 128 mode, double sided
>single density or double sided double density?

Basically all of the 5.25" disks I use in my 1571 are double density; double
density should work just fine.  What does NOT work, in my experience, is
HIGH density disks.  These are higher density than double density, and I don't
think the two are compatible.

-Rob Knop
rknop@tybalt.caltech.edu

desimone@cse.uta.edu (David Desimone) (05/01/91)

In article <1991Apr28.082406.5055@nntp-server.caltech.edu> rknop@nntp-server.caltech.edu (Robert Andrew Knop) writes:
>Basically all of the 5.25" disks I use in my 1571 are double density; double
>density should work just fine.  What does NOT work, in my experience, is
>HIGH density disks.  These are higher density than double density, and I don't
>think the two are compatible.

That's right, a high-density (or quad density) disk requires the disk
circuitry to switch to a much stronger write signal, and the 1571
hardware can't generate enough magnetic field to write to one of these
disks.

Interestingly, the SFD1001, a high-density drive, has this exact same
problem, so that you must use double-density disks with it, even though
it uses more density than that.  With this drive I recommended that you
get GOOD QUALITY double-density disks.  I have not had a problem, except
when I tried to format a high density disk in the SFD.  :)

-- 
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