>From: allisonp@world.std.com (Allison J Parent)

>< You're right that 360 KB floppies are not officially rated for 96 TPI,
>< but in practice they seem to work fine.  For years the disk companies ha
>
>I'd like to know how you will get a fd55B, MPI502b or any other 360k 
>floppy to write data on anything other than the 40 possible cylinders
>the stepper positions to.
>
>To do 96tpi you need a FD55F or FD55G that can position to any one
>of the possible _80_ cylinders possible.

Ahh I think the problem here is terminology.  I'm 99% sure that when the
original poster said "floppy", they meant the disk not the drive (that
would explain the reference to peeling off the hub ring).  That's certainly
what I meant.  I absolutely agree that a 48 TPI *drive* is useless on RX50
disks.

------------------------------------------------------------
>From: Erno Palonheimo <esp@stip.net>

>I was trying to get the RX50 bootfloppy written using PUTR software. I
>formatted a 360k drive and right after that I tried to COPY/DEVICE/BINARY
>the bootdisk image onto the floppy but it failed complaining about General
>Failure. Is this the right method of doing the disk images? I tried
>without /BINARY but it didn't work either.

"General failure" sounds like a DOS error message not a PUTR one, so it
may be that the disk wasn't mounted as a PUTR pseudo-device so PUTR assumed
you wanted to talk to the drive using DOS (which is how it accesses any
un-MOUNTed drive).  The proper sequence is like this (from inside PUTR):

format b: /rx50
mount b: /foreign /rx50
copy/file/dev foobar.bin b:
quit

If you did do that and it still didn't work, please send me the particulars
so I can investigate.  You probably don't want to use /BINARY on the COPY
command for RX50s, since in this case that means to use raw sector order
rather than the interleaved order used by the RQDX3 firmware and emulated
by all other PDP-11/VAX RX50 device drivers.  So it would appear to write
OK but the resulting disk would be scrambled.

John Wilson
D Bit