[HECnet] RT-11 filesystems, was Re: DECnet-RT?

[Dave McGuire]

On 3/31/20 10:02 AM, Robert Armstrong wrote:
> RT11 has an architectural limit of 32Mb per file system.  Most disk
> drives, even way back then, are bigger than that and have to be
> partitioned if you want to use all the space.  This is an RT11 thing,
> not a CDROM nor a PDP-11 nor a simh, feature.

  So, about that.  And please forgive the non-HECnet-related question.

  Like everyone here, I've run RT-11 since the dawn of time.  But I've
never run it on a disk that's larger than 32MB that is also not MSCP.

  On a (real) system at the museum the other day, I noticed that RT-11
has a driver for the RM02/RM03, a 67MB drive.  I went looking as I'm
bringing up a Fuji M2284K SMD drive, which (on an Emulex SC21 Unibus
controller) emulates two RM02s.  If RT-11 cannot partition an RM02
because it's not MSCP, then why does it have a driver for it?  Will it
just use the first 32MB?

  Or (similarly to Ethernet) was it just there to use "raw"?  I know of
one installation (on an 11/70) that used RM02s for raw storage of
digitized audio, no filesystem.

              -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA