🚀 go-pugleaf

In article <C15zHy.I5A@boulder.parcplace.com> imp@boulder.parcplace.com (Warner Losh) writes:
>In article <5282018@zl2tnm.gen.nz> don@zl2tnm.gen.nz (Don Stokes) writes:
>>Unreliability?  The damn things just don't work.  The RX50 has much the same
>>head as a double density drive.  It can't make head nor tail of the weak
>>signal recorded on HD media.
>
>RX-50 uses the same signal strength as the double density drives.  The
>IBM-PC uses a much higher signal to write to HD disks.  The RX-50
>doesn't have the signal strength to effectively magnetize the oxide
>particles in HD disks.  The HD disks have different magnetic
>characteristics than QD disks and should not be used in RX-50 dirves.
>
>From my personal experience, I've had little to no problem with 48tpi
>disks in the Rainbow.  The better quality ones always work, while the
>ultra cheap ones do seem to have a few bad sectors.  The 96tpi QD
>disks seem to have fewer problems still.

This is consistent with my experience.  Today, dd disks are usually pretty
good, so they can be used on RX50 without resorting to qd disks.  However,
there are really cheap dd disks that are barely acceptable for 360K PC
applications, and shouldn't be used with RX50.  In earlier times there was
more of a distinction between dd and qd disks.

In any case, the hd disks are unusable since they are inherently magnetically
"weaker" and use higher signal strength to record the data, which is not
suitable for the RX50-worthy media.  On PC's, a similar situation can be
contrived by formatting as 360K an hd disk and attempting to read it on a
48 TPI PC drive.  Some media will flakily work, but a lot of them won't.

cjl